WASHINGTON/MOSCOW, March 6 -- U.S. President Barack Obama Thursday proposed a diplomatic resolution once again to the ongoing crisis in Ukraine, while his Russian counterpart Vladimir Putin said Moscow acted in accordance with international law.

In an hour-long phone talks, Obama told Putin that Russia's actions in Crimea, an autonomous republic in southern Ukraine, "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.

Earlier in the day, the Obama administration announced visa bans and assets freeze against those Russians and Ukrainians involved in what it called Russia's takeover of Crimea, following suspension of trade and investment talks and military-to-military engagement with Russia.

"President Obama indicated that there is a way to resolve the situation diplomatically, which addresses the interests of Russia, the people of Ukraine, and the international community," the White House said in a readout of the talks, the second this week.

It said Obama's suggestions included direct talks between the governments of Ukraine and Russia; the deployment of international monitors to ensure the rights of all Ukrainians are protected, including ethnic Russians; the return of Russian forces to their bases in Crimea; and international support for presidential elections in Ukraine in May.

Obama also said U.S. Secretary of State John Kerry would continue discussions with his Russian counterpart Sergei Lavrov, though the pair had reached no agreement following their talks in Paris and Rome on Wednesday and Thursday.

Meanwhile, the Kremlin's press service said Putin and Obama discussed "the acute situation" in Ukraine during their conversation "requested by the U.S. side."

"The discussion revealed the divergence of approaches to and opinions of the causes of the current crisis and the existing state of affairs," the Itar-Tass news agency quoted the Kremlin as saying.

Putin said the current Ukrainian leadership, which had come to power "in an unconstitutional way as a result of government coup and lacked a national mandate," was dictating illegitimate decisions to the eastern and southeastern regions of Ukraine and Crimea.

Moscow could not ignore the requests for help addressed to it and was acting adequately and in full compliance with international law, he told Obama.

The Russian president also emphasized the importance of Russian-U.S. relations for maintaining world stability and security.

"These relations must not be sacrificed to differences over individual, albeit tangible, international problems," Putin said.

Putin and Obama agreed that Lavrov and Kerry would "go ahead with intensive contacts" to discuss Ukraine's crisis, according to the Kremlin.

The mostly Russian-speaking Crimea, home to Russia's Black Sea Fleet, has become the epicenter of the ongoing crisis in Ukraine since President Viktor Yanukovych was ousted by parliament on Feb. 22.

Russia did not recognize Ukraine's new government put in place after pro-Russian Yanukovych's ouster, and called the events in the neighboring country a coup.