Crimea has returned to its historical Russian homeland and will never again be part of Ukraine, its prime minister has said.
Sergei Aksyonov told the BBC the annexation of the peninsula by Russia one year ago had been a "democratic act".
Meanwhile, in a pre-recorded interview which aired on Sunday, Russian President Vladimir Putin revealed that Russia was preparing to use nuclear weapons in fear of an attack amid the Ukraine crisis, according to claims aired on state TV on Sunday (15 March).
In the film, Putin said the life of ex-Ukrainian leader Viktor Yanukovych had been in danger, and added Russians in Crimea were in danger before Russia annexed it.
In a documentary, titled 'Crimea: The Road Back Home', Putin said on Russia's desire to use nuclear weapons: "We were ready to do this ... [Crimea] is our historical territory. Russian people live there. They were in danger. We cannot abandon them."
The leader, who said he ordered the annexation weeks before a referendum was held, has not been seen in public since 5 March, leading to speculation that he has suffered a stroke or has been ousted in a coup.
Despite international condemnation, Crimea was formally absorbed into Russia on 18 March after a disputed referendum boycotted by Crimeans loyal to Ukraine.