The parliament in Ukraine's crisis-hit Autonomous Republic of Crimea on Thursday voted to become part of Russia.
A total of 78 of 86 lawmakers present in parliament voted for the bill during the closed session.
"We took a decision to join the Russian Federation. We think that it would be much better and more comfortable for us," said Sergey Tsekov, deputy speaker of the Crimean parliament.
The Crimean lawmakers have also asked Russian President Vladimir Putin to consider the request of their region to join Russia.
The parliament's session has also set a referendum on March 16, which would ask whether the Crimea people would like to remain part of Ukraine or join Russia.
In Ukraine, there is no law on local referendums, so the referendum in Crimea may be considered as illegal.
The mostly Russian-speaking Crimea is now the epicenter of the ongoing crisis. Some 50 armed men carrying Russian navy flags took control of two airports in the Crimean capital of Simferopol and the second-largest city of Sevastopol on Friday, one day after gunmen seized the local parliament and government buildings and raised Russian flags over them.
On Wednesday, the Ukrainian court issued an arrest warrant for Crimean Prime Minister Sergey Aksenov, who was elected to his position in the closed session of the local parliament.
Alexandr Turchynov, parliament speaker and acting president of Ukraine, issued the decree declaring illegal the appointment of Aksenov.
Earlier, Aksenov proposed a referendum to extend Crimea's autonomy status on March 30.