MOSCOW - Vladimir Putin, the Russian president, has been granted the authority to use the country’s armed forces in Ukraine as pro-Russian unidentified gunmen continue to control the state buildings in the southeastern Ukrainian region of Crimea.

The Federation Council, the upper house of the Russian parliament, voted overwhelmingly to back a proposal to use "the armed forces of the Russian Federation on the territory of Ukraine until the normalisation of the socio-political situation in that country,” the Federation Council said yesterday.

Earlier in the day, Putin requested the power in question from the Federation Council "in connection with the extraordinary situation in Ukraine and the threat to the lives of Russian citizens,” according to a Kremlin statement.

Crimea has a majority of ethnic Russians and the region’s administration is defying the new Kiev government that ousted Moscow-backed Ukrainian President Viktor Yanukovich.

The Kemlin said that Putin has not yet taken a decision on sending troops to Ukraine.

"It is the president who takes the decision. For the moment, this decision has not been taken,” Kremlin spokesman Dmitry Peskov told Russia’s RIA Novosti news agency.

Meanwhile, Ukraine’s boxer turned renowned politician Vitali Klitschko urged parliament to mobilise the army.

"Parliament must ask the army’s commander-in-chief to declare national mobilisation after the start of Russian aggression against Ukraine,” Klitschko said in a statement. He also asked for the United Nations Security Council to gather urgently for talks on the crisis.

Appeal to Putin

The developments come after Sergiy Aksyonov, the pro-Russian prime minister of the Crimea region, appealed to Putin for help to ensure peace in the semi-autonomous region where unidentified gunmen believed to be Russian are guarding the state buildings, including the local parliament.

Al Jazeera’s Tim Friend, reporting from Kiev, has said that the country’s acting president called together the security council, which includes his senior aides, to discuss the tactics to be followed next.

"This (the approval of Putin’s request) is formalisation of what they regard as already happening — the Russian annexation of Crimea. They want the UN to be involved and calm the situation in the region,” he said.

According to Friend, the tense atmosphere in Crimea is spreading to other parts of the country such as the eastern Ukrainian city of Donetsk, where EU and Russia supporters have clashed.

"This is a very worrying situation,” he said.

Oleksandr Turchynov, Ukraine’s interim president, issued a statement on Saturday declaring that his administration did recognise the authority of Crimea administration.

Russia, denying accusations of staging an aggression against its neighbour country, says any military movement in Crimea is part of the agreement in question that was previously made.

Moscow is also refusing to hold talks with Kiev under the auspices of that agreement, which guarantees Ukraine’s territorial integrity, Interfax news agency quoted Ukrainian Foreign Minister Andrij Deshchitsya as saying on Saturday.

Kiev had asked for consultations with Moscow after declaring that the Ukrainian government would not be drawn into a military conflict by Russian "provocations”.

Warning from Obama

On Friday, the US President Barack Obama warned Putin that Moscow would pay "costs” if it is to stage a military intervention. Obama said he was "deeply concerned by reports of military movements taken by the Russian Federation inside of Ukraine”.

Ukraine’s new government, which came to power after the ousting of Viktor Yanukovich, has called for fresh presidential elections on May 25, a move opposed by the administration in Crimea.