Ukraine Crisis: Obama Urges Diplomatic Solution but Putin Remains Defiant

US President Barack Obama has pushed for a diplomatic solution to the Ukraine crisis in a telephone conversation with Vladimir Putin, but the stalemate continues after the Russian President insisted his action was triggered by Kiev's "illegitimate decisions" on the Russian-speaking Crimea region.

Obama told Putin in an hour-long talk that his government was taking steps in coordination with its European partners over Russia's violation of Ukraine's sovereignty, the White House revealed.

The two leaders spoke after regional Crimean lawmakers voted to adopt a resolution calling for secession from Ukraine and union with Russia, and set a March 16 referendum -- moves strongly condemned by the west.

"President Obama emphasised that Russia's actions are in violation of Ukraine's sovereignty and territorial integrity, which has led us to take several steps in response, in coordination with our European partners," the White House said in a statement.

Obama told Putin he believed there were ways to resolve the situation diplomatically, protecting the interests of Russia, Ukraine and the international community.

Following the talk, Putin said he still had differences with the US, adding that his country's intervention in Crimea was necessitated by Kiev's "absolutely illegitimate decisions on the eastern, southeastern and Crimea regions.

"Russia cannot ignore calls for help in this matter and it acts accordingly, in full compliance with the international law," Putin said, according to Haaretz newspaper.

In his talk with Putin, Obama had presented a broad outline for a diplomatic solution to the crisis.

"As a part of that resolution, the governments of Ukraine and Russia would hold direct talks, facilitated by the international community; international monitors could ensure that the rights of all Ukrainians are protected, including ethnic Russians; Russian forces would return to their bases; and the international community would work together to support the Ukrainian people as they prepare for elections in May," the president said.

With the Crimean parliament deciding to hold a referendum, the spectre of secession has become more imminent and the Tatars in Crimea have said they will boycott the vote.

Ukrainian Prime Minister Arseniy Yatsenyuk said the Crimean lawkamers' decision to hold the referendum was "a farce".

The US and the European Union have announced fresh sanctions on Russia, and Obama said in Washington the referendum "would violate the Ukrainian constitution and violate international law."