Ukraine puts armed forces on full combat alert

Ukraine has put its armed forces on full combat alert and warned Moscow that any military intervention in the country would lead to war after upper house of Russia's parliament agented Vladimir Putin, the Russian president, the authority to use the country's armed forces in its neighbour.

After a more than three-hour meeting with security and defence chiefs, Oleksander Turchinov, Ukraine's interim president, said there was no justification for what he called Russian aggression against his country.

Turchynov said that authorities had boosted security around the country's nuclear facilities, airports and other "strategic facilities".

Standing beside Turchinov, Arseny Yatseniuk, Ukraine's prime minister, said he had urged Russia to return its troops to base in the Crimea region during a phone call with Dmitry Medvedev, Russia's prime minister, and called for talks.

"I am convinced that Russia will not launch an intervention as this would mean war and the end of all relations between the two countries,"he said.

The Federation Council, the upper house of the Russian parliament, voted overwhelmingly on Saturday to back a proposal by Putin 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 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.

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

'No decision yet'

A Kremlin statement quoted by Russia's RIA Novosti news agency said that Putin has not yet taken a decision on sending troops to Ukraine.

European Union foreign policy chief Catherine Ashton urged Russia to refrain from deploying its armed forces in Ukraine and to abide by international law.

The United Nations Secretary-General Ban Ki-moon called for the immediate restoration of calm in Ukraine as the Security Council held emergency talks on the escalating crisis.

Al Jazeera's Tim Friend, reporting from Kiev, says, "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.

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.

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.

The interim government has issued an arrest warrant for Yanukovich, accusing him of being responsible for the deaths of at least 70 protesters on February 21 protests in Kiev.