03/03/2014 10:19 GMT | Updated 03/03/2014 13:59 GMT

Russian Black Sea Fleet Gives Ukraine Navy In Crimea Deadline To 'Surrender Or Face Storm' (VIDEO)

Vladimir Putin has moved to increase pressure on Kiev by giving Ukrainian naval forces in Crimea a deadline of Tuesday morning to surrender or face a Russian bombardment.

According to a Ukrainian defense ministry spokesman, Russia's Black Sea Fleet has demanded the crew of two Ukrainian warships immediately surrender or face a military assault.

"If they do not surrender before 5 am tomorrow, we will start a real storm against units and divisions of the armed forces across Crimea," reported the Interfax news agency. The ultimatum was reportedly given by Alexandr Vitko, chief commander of Russia's Black Sea fleet.

According to AP, four Russian navy ships are currently in Sevastopol's harbour blocking Ukraine's anti-submarine warship Ternopil and the command ship Slavutych.

Russian marines guard the Orsk Russian landing ship anchored in Sevastopol

Russian forces have captured the Crimean Peninsula and there are concerns that it might seek to seize control of other parts of the country. Interim Ukrainian leader Arseniy Yatsenyuk said there was no reason for Russia to invade and warned that "we are on the brink of disaster".

Earlier on Monday, Russia demanded Ukrainian politicians return to the agreement of February 21, in which elections were promised for later this year. Across Europe an in the US, diplomats condemned Moscow for the military escalation, however Russian Foreign Minister Sergey Lavrov remained resolute that the Kremlin's actions were legitimate.

He told a UN meeting in Geneva that the invasion of Crimea was "a question of defending our citizens and compatriots, ensuring human rights, especially the right to life."

Overnight, it was reported by Interfax that Russia fighter jets violated Ukrainian airspace over the Black Sea forcing Ukraine's air force to scramble a Sukhoi SU-27 interceptor.

Writing for the WorldPost, Rajan Menon, the Anne and Bernard Spitzer Chair professor of political science at CCNY, argues that Putin's intentions in Ukraine remain unclear.

"From Putin's perspective, Yanukovych, having become president in 2010 after an election that international observers deemed to be largely free and fair, had the legal right to ice the AA and to turn to Russia for aid," writes Menon. "Thus the crowds that drove him from office engaged in a coup. Where the West sees heroism and democracy, Putin sees illegality and extremism."