OBAMA: 'We May Be Able To De-Escalate' The Ukrainian Crisis

President Barack Obama expressed hope Tuesday night that the crisis in Ukraine can be "de-escalated" after days of Russian aggression in the region of Crimea.

"We now have a situation in which the Russians, I think, are engaging in a fundamental breach of international law in sending troops into the country to try to force the hands of the Ukrainian people," Obama said at a fundraiser for the Democratic Senatorial Campaign Committee Tuesday night.

"We may be able to de-escalate over the next several days and weeks, but it's a serious situation and we're spending a lot of time on it."

Obama's comments came after he spent about an hour on the phone with Chancellor Angela Merkel of Germany, in a call the White House said focused on the importance of de-escalating the situation.

"The leaders expressed their grave concern over Russia's clear violation of Ukrainian sovereignty and territorial integrity and agreed on the importance of de-escalating the situation, including through the deployment international observers and human rights monitors, and of initiating direct talks between Russia and Ukraine," the White House said of the call in a statement.

It was perhaps his most optimistic public comments to date on the crisis. Obama, Secretary of State John Kerry, and other U.S. officials have spent days urging Russian President Vladimir Putin to pull back his forces, threatening sanctions and "isolation" if Putin keeps pushing forward.

On Tuesday, Putin showed little signs of backing down, saying in a press conference that Russia has a right to defend Russian-speakers in Crimea by "all means" necessary. He did say, however, that military force would be a "last resort." Russian Foreign Minister Sergei Lavrov said Wednesday that pro-Moscow forces in the Crimea region are not taking orders from the Russian government.

Obama suggested international monitors should go to Ukraine to protect the rights of Russian-speaking people.