WASHINGTON -- President Obama said he was "deeply concerned" on Friday over reports that Russian troops are meddling in Ukraine as armed men took up positions in Ukraine's Crimean region.

"We are now deeply concerned by reports of military movements taken by the Russian Federation inside Ukraine," Obama said in brief comments at the White House. He added, "It would be a clear violation of Russia's commitment to respect the independence and sovereignty and borders of Ukraine and of international laws.

"Any violation of Ukraine's sovereignty and territorial integrity would be deeply destabilizing, which is not in the interest of Ukraine, Russia or Europe," he said.

MORE: http://www.usatoday.com/story/news/politics/2014/02/28/obama-ukraine-russia-crimea/5906695/