Armed men believed to be Russian military march in the village outside Simferopol, Ukraine, on Friday, March 7. Ukrainian officials and Western diplomats accuse Russia of sending thousands of troops into the Crimea region in the past week, a claim Russia has denied. The crisis in the former Soviet republic has revived concerns of a return to Cold War relationships. Follow the evolving story on CNN's live blog.
Pro-Russia protesters demonstrate outside the Belbek Air Base outside Sevastopol, Ukraine, on Thursday, March 6.
A Ukrainian Navy officer looks at the scuttled, decommissioned Russian vessel Ochakov from the Black Sea shore outside the town of Myrnyi, Ukraine, on March 6. In the early hours of the day, Russian naval personnel scuttled the ship, blockading access for five Ukrainian Naval vessels now trapped inside of the Southern Naval Headquarters.
A member of the Russian military patrols around Perevalne, Ukraine, on March 6.
Servicemen guard a checkpoint at a Ukrainian Navy base in Perevalnoe, Crimea, on March 6.
Ukrainian troops guard the Belbek air base outside Sevastopol, Ukraine, on March 6.
A woman walks past barricades on March 6 that were set up by anti-government protesters in Kiev's Independence Square.
A sailor guards the Ukrainian Navy ship Slavutych in the Bay of Sevastopol on Wednesday, March 5.
People wait in line for food distribution in Independence Square on March 5.
Ukrainian sailors carry meat to their vessel in the Sevastopol harbor on March 5.
Riot police stand at the entrance of a regional administrative building during a rally in Donetsk, Ukraine, on March 5.
A Ukrainian police officer gives instructions to members of the media in front of the business class lounge of the Simferopol airport on March 5.
Pro-Russia demonstrators wave a Russian flag after storming a regional administrative building in Donetsk on March 5.
Demonstrators break a police barrier as they storm a regional administrative building in Donetsk on March 5.
Ukrainian military recruits line up to receive instructions in Kiev's Independence Square on Tuesday, March 4.
People stand on the Ukrainian Navy ship Slavutich while it's at harbor in Sevastopol on March 4. Mattresses were placed over the side of the ship to hinder any attempted assault.
Ukrainian troops watch as a Russian navy ship blocks the entrance of the Ukrainian navy base in Sevastopol on March 4.
A woman photographs pro-Russian soldiers guarding Ukraine's infantry base in Perevalnoye, Ukraine, on March 4.
U.S. Secretary of State John Kerry, wearing a blue scarf, visits a shrine March 4 for the people who were killed during anti-government protests in Kiev last month.
Yuli Mamchun, the commander of the Ukrainian military garrison at the Belbek air base near Sevastopol, salutes on March 4.
Russian soldiers stand guard at the Belbek air base on March 4.
Ukrainian military members march at the Belbek air base on March 4.
Russian soldiers fire warning shots to keep back Ukrainian military members at the Belbek air base on March 4.
A Ukrainian airman puts the Ukrainian national flag over the gate of the Belbek air base as they guard what's left under their control on March 4.
Russian soldiers aim a grenade launcher and machine gun as they guard positions at the Belbek air base on March 4.
Ukrainian seamen stand guard on the Ukrainian navy ship Slavutich in the Sevastopol harbor on Monday, March 3.
Oleg, a Ukrainian soldier, kisses his girlfriend, Svetlana, through the gates of the Belbek base entrance on March 3. Tensions are high at the base, where Ukrainian soldiers were standing guard inside the building while alleged Russian gunmen were standing guard outside the gates.
Wives of Ukrainian soldiers walk past Russian soldiers to visit their husbands guarding a military base in Perevalnoye on March 3.
A Russian soldier guards an area outside Ukraine's military base in the village of Perevalnoye on March 3.
A sailor looks out a window near the entrance to the Ukrainian navy headquarters in Sevastopol on March 3.
Armed men in military uniform walk outside a Ukrainian military unit near Simferopol on Sunday, March 2. Hundreds of armed men in trucks and armored vehicles surrounded the Ukrainian base Sunday in Crimea, blocking its soldiers from leaving.
Soldiers walk outside a Ukrainian military base in Perevalne, Ukraine, as a local resident waves a Russian flag March 2.
Demonstrators shout during a rally in Kiev's Independence Square on March 2.
Ukrainian soldiers, left, and unidentified gunmen, right, stand at the gate of an infantry base in Perevalnoye on March 2.
Ukrainian soldiers guard a gate of an infantry base in Perevalnoye on March 2.
A woman cries during a rally in Independence Square on March 2.
Protesters hold flags of the United States, Germany and Italy during a rally in Independence Square on March 2.
People attend a morning prayer service at Independence Square on March 2.
A soldier and a truck driver unload bread outside the Ukranian navy headquarters in Sevastopol, Ukraine, on March 2.
Heavily armed troops, displaying no identifying insignia and who were mingling with local pro-Russian militants, stand guard outside a local government building in Simferopol, Ukraine, on March 2.
A woman waits in front of unidentified men in military fatigues who were blocking a base of the Ukrainian frontier guard unit in Balaklava, Ukraine, on Saturday, March 1.
U.S. President Barack Obama, in the Oval Office of the White House, talks on the phone March 1 with Russian President Vladimir Putin.
Troops stand guard in Balaklava on March 1.
Heavily armed soldiers displaying no identifying insignia maintain watch in Simferopol, Ukraine, on March 1.
People gather around the coffin of a man who was killed during clashes with riot police in Independence Square.
Pro-Russian activists hold Russian flags during a rally in the center of Donetsk, Ukraine, on March 1.
Pro-Russian activists clash with Maidan supporters as they storm the regional government building in Kharkiv, Ukraine, on March 1.
A protester stands at a memorial March 1 for the people killed in clashes at Independence Square.
Armed men patrol outside the Simferopol International Airport in Ukraine's Crimea region on Friday, February 28. Simferopol is the regional capital.
An image provided to CNN by a local resident shows Russian tanks on the move in Sevastopol, Ukraine.
Russian troops block a road February 28 toward the military airport in Sevastopol, Ukraine. The Russian Black Sea Fleet is based at the port city of Sevastopol.
Armed men stand guard in front of a building near the Simferopol airport on February 28.
An armed man wearing no identifying insignia patrols outside Simferopol International Airport on February 28.
Police stand guard outside the Crimea regional parliament building Thursday, February 27, in Simferopol. Armed men seized the regional government administration building and parliament in Crimea.
Police intervene as Russian supporters gather in front of the parliament building in Simferopol on February 27.
A man adds fuel to a fire at a barricade in Independence Square on February 27. Dozens of people were killed last week during clashes between security forces and protesters.
Pro-Russia demonstrators wave Russian and Crimean flags in front of a local government building in Simferopol on February 27.
Barricades in front of a government building in Simferopol on February 27 hold a banner that reads: "Crimea Russia." There's a broad divide between those who support the pro-Western developments in Kiev and those who back Russia's continued influence in Crimea and across Ukraine.
Protesters stand in front of a government building in Simferopol on February 27. Tensions have simmered in the Crimea region since the Ukrainian president's ouster.
Protesters in support of the president's ouster rally in Independence Square, which has been the center of opposition, on Wednesday, February 26.
Security forces stand guard during clashes between opposing sides in front of Crimea's parliament building in Simferopol on February 26.
Pro-Russian demonstrators, right, clash with anti-Russian protesters in front of a government building in Simferopol on February 26.
A police officer gets pulled into a crowd of Crimean Tatars in Simferopol on February 26. The Tatars, an ethnic minority group deported during the Stalin era, is rallying in support of Ukraine's interim government.
A man places flowers at a barricade near Independence Square on February 26.
On February 26 in Kiev, A woman holds a photograph of a protester killed during the height of tensions.
Police guard a government building in Donetsk on February 26.
Protesters remove a fence that surrounds Ukraine's parliament in Kiev on February 26.
People sing the Ukrainian national anthem at Independence Square on Monday, February 24.
Gas masks used by protesters sit next to a barricade in Independence Square on February 24.
A woman cries February 24 near a memorial for the people killed in Kiev.
People wave a large Ukrainian flag in Independence Square on Sunday, February 23.
Two pro-government supporters are made to pray February 23 in front of a shrine to dead anti-government protesters.
A man and his daughter lay flowers at a memorial for protesters killed in Independence Square.
Former Prime Minister Yulia Tymoshenko speaks at Independence Square on Saturday, February 22, hours after being released from prison. Tymoshenko, considered a hero of a 2004 revolution against Yanukovych, was released after 2½ years behind bars.
Tymoshenko is greeted by supporters shortly after being freed from prison in Kharkiv on February 22.
A protester guards the entrance to Yanukovych's abandoned residence outside Kiev on February 22.
Anti-government protesters guard the streets next to the presidential offices in Kiev on February 22.
Anti-government protesters drive a military vehicle in Independence Square on February 22. Many protesters said they wouldn't leave the square until Yanukovych resigned.
Ukrainian lawmakers argue during a session of Parliament on Friday, February 21.
Men in Kiev carry a casket containing the body of a protester killed in clashes with police.
Protesters cheer after news of an agreement between the opposing sides in Kiev on February 21.
- NEW: Ukraine's interim prime minister tells "separatists" their actions are unlawful
- French foreign minister warns of more sanctions against Russia if it doesn't act
- Russian parliament says it'll back Crimea separation vote despite sanctions threat
- The United States and EU have threatened asset freezes, travel bans and visa bans
Moscow (CNN) -- Russia's parliament gave its defiant support Friday to Crimean lawmakers who want to see their region split from Ukraine and join Russia, saying no sanctions imposed by the United States or Europe will change its mind.
A delegation from the Crimean parliament, in Moscow a day after its lawmakers voted unanimously to split from Ukraine, said it would put the decision to a public vote on March 16.
But Ukrainian interim Prime Minister Arseniy Yatsenyuk has condemned those backing a split.
Crimea, an autonomous region in southern Ukraine with an ethnic Russian majority and strong cultural ties to Russia, has become the epicenter of a battle for influence between Moscow, Kiev and the West.
Valentina Matvienko, the speaker of Russia's upper house of parliament, told the Crimean delegation it would "support and welcome" any decision made by the Crimean people to become a part of Russia.
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"We have no rights to leave our people when there's a threat to them. None of the sanctions will be able to change our attitude," Matvienko said.
The delegation was greeted with applause in the lower house, where the speaker described the decision to hold the referendum as "dictated by the willingness to protect human rights and lives."
The Crimean government, which was installed a little more than a week ago after armed, pro-Russian men took over the parliament building in Simferopol, does not recognize the interim government in Kiev.
The authorities in Kiev, in turn, say the Crimean government is illegitimate.
Yatsenyuk, speaking Friday in Kiev, said: "I want to warn separatists and other traitors of the Ukrainian state who are trying to work against Ukraine, any of your decisions taken is unlawful, unconstitutional, and nobody in the civilized world is going to recognize the results of the so-called referendum of the so-called Crimean authorities."
He said he'd requested a second telephone conversation with Russian Prime Minister Dmitry Medvedev.
Yatsenyuk, who was in Brussels, Belgium, on Thursday as European Union talks on sanctions against Russia took place, insisted then that "Crimea was, is and will be an integral part of Ukraine."
U.S. President Barack Obama set out a potential solution to the crisis in Ukraine when he spoke to his Russian counterpart, Vladimir Putin, on Thursday, the White House said.
The proposal would include direct talks between Kiev and Moscow, the withdrawal of Russian forces to their bases, international support for elections due May 25, and the presence of international monitors to "ensure that the rights of all Ukrainians are protected, including ethnic Russians."
Obama also rejected the Crimean lawmakers' decision to call a referendum, saying: "In 2014, we are well beyond the days when borders can be redrawn over the heads of democratic leaders."
International observers are welcome to witness Crimea's upcoming referendum on joining the Russian Federation, the delegation of the newly installed Crimean parliament said in Moscow.
Map of Crimea
Map of Crimea
CNN reporter told to stop broadcasting
Stopping Crimea from rejoining Russia
Ukrainians react to Crimea referendum
Meanwhile, international monitors called in by Kiev will try again Friday to gain access to Crimea, which has been under effective Russian control for several days.
On Thursday, armed men at checkpoints turned back the 35-strong team from the Organization for Security and Co-operation in Europe, a regional security bloc.
But members of the OSCE team told CNN's Matthew Chance, who is traveling with them from Kherson in southern Ukraine toward the Crimean peninsula, that they intend to be more assertive Friday as they seek to get in and assess the situation.
Asset freezes, visa bans
As they seek to put the diplomatic squeeze on Russia to pull back its forces from Crimea and negotiate with Kiev, EU nations announced Thursday they will suspend bilateral talks with Russia on visa matters and have threatened travel bans, asset freezes and cancellation of a planned EU-Russia summit.
French Foreign Minister Laurent Fabius told French public radio Friday that tougher measures are planned if Moscow doesn't act to de-escalate the situation.
"Without very prompt results, there will be further measures against Russian officials and companies. Those could be asset freezes, cancellations, visa denials," he told France Info.
"And if another attempt is made, then we would enter into something completely different -- that is to say serious consequences for the relations between Europe and Russia."
The United States also has taken action. The State Department has imposed a visa ban on Russian and Ukrainian officials and others that it said are responsible for, or complicit in, threatening Ukraine's sovereignty and territorial integrity. Obama has signed an executive order laying the groundwork for sanctions against individuals and entities responsible for the crisis.
The Paralympic Games get under way Friday in the Russian city of Sochi, and Putin is expected to attend the opening ceremony.
Ukrainian Paralympic Committee chief Valeriy Suskevich appealed for peace in his country and said he'd made the same request of Putin at a meeting Thursday night.
"We are staying in order to be remembered, for Ukraine to be remembered as the state which sent a unified team," he said at a news conference. "We've taken the decision to raise the flag of the independent sovereign state of Ukraine here at the Paralympic Games."
Ukraine's sports minister will not be attending.
Britain, the Netherlands, Canada and Poland are among those who also have said they will stay away. Earlier this week, the White House canceled a presidential delegation to the Paralympic Games.
Moscow has denounced the events that led to Ukrainian President Viktor Yanukovych's ouster in late February as an illegitimate coup and has refused to recognize the new Ukrainian authorities, putting Russia and Ukraine on a collision course over control of Crimea.
Putin has insisted he has the right to use military force in Ukraine if necessary to protect ethnic Russians in Crimea. But Ukrainian officials say no threat exists and that Putin is using it as a pretext to control the region.
The peninsula was part of Russia until Soviet leader Nikita Khrushchev gave it to Ukraine in 1954. Ukraine was then part of the Soviet Union. Russia has a major naval base in the port city of Sevastopol, and thousands of troops are stationed there.
Russian speakers make up about 60% of the population, but around a quarter are Ukrainian and 12% are Crimean Tatar, a predominately Muslim minority. Neither of the latter two groups would welcome a switch to Russian control.
Meanwhile, a second Russian naval vessel was scuttled Friday morning at the entrance to Lake Donuzlav, an inlet on the western coast of Crimea home to a Ukrainian naval base.
Viktor Shmihanovsky, vice commander of the base, told CNN that the inlet is now sealed off and that several Ukrainian naval ships are trapped inside. Russian vessels remain in the waters beyond the blockade, he said.
Interpol asked to arrest Yanukovych
The EU and the United States also announced plans to freeze the assets of ousted leader Yanukovych, who turned his back on a trade deal with the EU in favor of one with Russia.
The rejected trade deal prompted months of protests that culminated in February with bloody street clashes that left dozens dead and Yanukovych out of office.
Back in Kiev on Friday, Yatsenyuk, the interim prime minister, said an agreement to sign an EU trade deal reached Thursday, and the offer of an EU financial aid package worth $15 billion, were the result of historic unity with EU members.
"We are leading Ukraine into the European Union," he said.
Interpol said it is reviewing a request by Ukrainian authorities that would allow for the arrest of Yanukovych on charges of abuse of power and murder, an allegation tied to the deaths of protesters.
Read: Ukraine PM: Crimea 'was, is and will be an integral part of Ukraine'
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Read: Complete coverage on the Ukraine crisis
Live: Ukraine crisis updates
Map: How Ukraine is divided
CNN's Laura Smith-Spark wrote this report from London, and CNN's Alla Eshchenko reported from Moscow. CNN's Chelsea J. Carter, Ursin Caderas and Tim Schwarz contributed to this report.