The Crimean Parliament voted on Thursday to hold a referendum on reunification with Russia on March 16, officials said.
Russian President Vladimir Putin has been advised of Crimea's desire to join the Russian Federation, Kremlin spokesman Dmitry Peskov told state television.
Moscow deployed its forces last week in Ukraine's Crimean Peninsula, a majority Russian-speaking region, claiming it was protecting ethnic Russians and Russia's interests in the area.
Russia's Black Sea Fleet is based in the Crimean city of Sevastopol, which has been the naval force's home port since the 18th century.
Soviet leader Nikita Khrushchev gave the Crimean Peninsula to Ukraine in 1954.
About 200 protesters gathered outside the Crimean Parliament to demand that the region become part of Russia.
The demonstrators, some wearing Russian flags, chanted that they wanted Crimea to be part of "mother Russia" and sang patriotic songs about the region's ties to Russia.
"I am convinced that the people will vote in favor of leaving Ukraine and joining Russia," a protester who identified himself only as Anatoly told Efe.
The Crimean Peninsula, located on the northern coast of the Black Sea, is home to 2 million people; ethnic Russians make up 60 percent of the population, while 25 percent of residents are ethnic Ukrainians and 12 percent are Crimean Tatars.
Ukraine's interim government has said that it will not relinquish Crimea.
Ukraine will not "hand over Crimea to anyone," Ukrainian interim Prime Minister Arseniy Yatsenyuk said Monday.
The United States, meanwhile, said Thursday it was imposing visa restrictions and personal sanctions on "individuals and entities" involved in the Russian military intervention in Crimea.
President Barack Obama has ordered the imposition of "visa restrictions on a number of officials and individuals, reflecting a policy decision to deny visas to those responsible for or complicit in threatening the sovereignty and territorial integrity of Ukraine," the White House's Office of the Press Secretary said in a statement.
"The President has signed an Executive Order that authorizes sanctions on individuals and entities responsible for activities undermining democratic processes or institutions in Ukraine; threatening the peace, security, stability, sovereignty, or territorial integrity of Ukraine; contributing to the misappropriation of state assets of Ukraine; or purporting to assert governmental authority over any part of Ukraine without authorization from the Ukrainian government," the statement said.
The crisis in Ukraine erupted at the end of November, when President Viktor Yanukovych backed away from plans to ink a pact with the European Union and instead signed a $15 billion financial-aid package with Russia.
Protesters took to the streets of Kiev and began occupying administrative buildings, prompting Ukraine's parliament, then controlled by Yanukovych's allies, to pass a package of laws on Jan. 16 restricting freedom of assembly, freedom of speech and other basic rights.
Violent clashes pitting demonstrators and riot police broke out three days later and left six dead and hundreds wounded.
Ukrainian officials and opposition leaders began seeking a negotiated solution to the crisis in the wake of the bloodshed.
The talks led to the resignation of Prime Minister Mykola Azarov on Jan. 28 and the repeal of the controversial anti-protest laws.
But more street battles pitting pro-European Union protesters against the security forces left dozens dead in February, and led to Yanukovych agreeing to call early presidential elections and then fleeing Kiev.
After Yanukovych left the city, many of his former allies in parliament turned against him and helped oust him from power and release his arch-rival, former Prime Minister Yulia Tymoshenko, from prison. EFE