‘This is a declaration of war . . . We are on the brink of disaster’

“This is a declaration of war... We are on the brink of disaster,” Ukraine prime minister Arseny Yatsenyuk warned, as Russian troops surrounded at least two military bases in Crimea and the country’s Naval commander defected to Moscow.

World leaders and the head of Nato echoed Kiev’s warning after pro-Russian forces took over government buildings and the two main airports in the region on the Black Sea where Russia has a naval base, heightening tensions.

Ukraine is fully mobilising its military and has called in its reservists to bases across the country, banned all military overflights on its territory and placed armed soldiers at all its airports.

Ukraine Navy commander Denys Berexovsky defected, calling on his soldiers to surrender to Russia. Kiev accused him of treason. Soldiers, believed to be Russian, are effectively in control in Crimea and have been pressing Ukraine military in at least two bases to hand over their weapons or they would storm in. Rows of personnel carriers are surrounding the bases.

The prime minister described the situation as a “red alert”, adding, “This is not a threat, this is the declaration of war on my country... We are on the brink of disaster”.

Acting president Oleksandr Turchynov said he could not reach Russian president Vladimir Putin or prime minister Dmitri Medvedev by telephone.

US President Barack Obama spoke to Mr Putin on Saturday night for 90 minutes, but the White House said there was no meeting of minds. Mr Obama asked him to engage with the new leadership in Kiev and to support international observers from the UN Security Council or the OSCE.

The secretary general of Nato, Anders Fogh Rasmussen, ahead of a special meeting with Ukrainian and Nato members, warned that Russia’s action “threatens peace and security in Europe” warning that Moscow must stop its military activity and threats and de-escalate tensions.

EU foreign ministers, including Eamon Gilmore, meet in an emergency session in Brussels today. They will consider sanctions against Russia and look again at those they agreed but shelved against the deposed Ukraine president and members of his government.

US secretary of state John Kerry is due to travel to Kiev tomorrow.