NATO and Russia have agreed to meet Wednesday for talks on the crisis in Ukraine.
The meeting in Brussels will be the first public contact between the Western defense alliance and Russia's envoys since Russian forces moved into Ukraine's Crimean peninsula late last week.
NATO said Tuesday the Russian military presence in Ukraine presents "serious implications for the security and stability of the Euro-Atlantic area."
Meanwhile in Paris, U.S. Secretary of State John Kerry is expected to meet Wednesday with Russian Foreign Minister Sergei Lavrov.
Kerry was in Kyiv on Tuesday to meet with Ukrainian officials and said the United States wants to see a de-escalation of the crisis.
At a fundraiser Tuesday night, Mr. Obama said Russia is breaching international law and using troops to "try to force the hands of the Ukrainian people." He told reporters earlier in the day that the international community wants to make sure the rights of Ukrainians are upheld.