In his brief remarks, Obama underlined the importance of supporting Ukraine during its political transition. That support, the president said, "is not only in the interest of the people of Ukraine and the international community but also in Russia's interest."
Russian President Vladimir Putin and Foreign Minister Sergey Lavrov told the Obama administration in various phone conversations this past week that it would remain respectful of Ukraine's territorial integrity.
Alluding to on-going events in Ukraine's mostly pro-Russian Crimea region, the president said:
"... we are now deeply concerned by reports of military movements taken by the Russian Federation inside of Ukraine."
On Thursday, government buildings in Crimea were seized by gunmen who raised Russian flags above the buildings. Early Friday, armed men whom Ukrainian Interior Minister Arsen Avakov claimed were Russian soldiers began patrolling the Simferopol airport in Crimea. Their presence, Avakov said, is regarded as "an armed invasion and occupation." There were also reports of Russian frigates patrolling the nearby port.
After acknowledging Russia's "historic relationship with Ukraine," Obama warned Russia that "any violation of Ukraine's sovereignty and territorial integrity would be deeply destabilizing" and "would represent a profound interference in matters that must be determined by the Ukrainian people."
"It would be a clear violation of Russia's commitment to respect the independence and sovereignty and borders of Ukraine, and of international laws. The United States will stand with the international community in affirming that there will be costs for any military intervention in Ukraine."
Obama characterized the situation in Ukraine as "very fluid," and noted that Vice President Joe Biden had recently spoken with Prime Minister Arseniy Yatseniuk "to assure him that in this difficult moment, the United States supports his government's efforts and stands for the sovereignty and territorial integrity and democratic future of Ukraine."
"The events of the past several few months remind us of how difficult democracy can be in a country with deep divisions. But the Ukrainian people have also reminded us that human beings have a universal right to determine their own future."