U.S. President Barack Obama on Wednesday once again warned Russia against further destabilizing Ukraine, but said Moscow was not seeking "military confrontation."

In an interview with CBS News, Obama said it was "absolutely clear" that Russia had violated Ukraine's sovereignty and territorial integrity by annexing Crimea last month and was continuing to do so by supporting "non-state militias" in eastern Ukraine.

"What I've said consistently is that each time Russia takes these kinds of steps, that are designed to destabilize Ukraine and violate their sovereignty, that there are going to be consequences," the president added.

Washington has targeted a number of key Russian and Crimean officials as well as a Russian bank following Moscow's move on Crimea. Obama signed an executive order in late March authorizing expanded sanctions against more individuals and entities as well as key sectors of Russia's economy including energy, banking, mining and defense.

The Ukrainian government on Monday night launched military operations to flush out pro-Russian militants who were occupying government buildings in the eastern part of the country, in which at least four people have been killed.

"The sharp escalation of the conflict" had placed Ukraine "in effect on the verge of civil war," Russian President Vladimir Putin told German Chancellor Angela Merkel over the phone on Tuesday.

Obama told CBS News that Russia was not seeking "military confrontation" with the United States despite the Ukrainian crisis.

"They're not interested in military confrontation with us, we don't need a war," he said. "What we do need is that countries like Ukraine can have relationships with their neighbors."

U.S. Secretary of State John Kerry left on Wednesday for Geneva for a Thursday meeting over Ukraine with the EU, Russia and Ukraine.

Moscow has rejected accusations that Russia was destabilizing Ukraine.

In a telephone conversation with Obama on Monday, Russian President Vladimir Putin denied that Moscow was interfering in Ukraine and urged the United States to use its influence to prevent bloodshed in Ukraine.