President Obama said he was "deeply concerned" by reports that uniformed Russian military and paramilitary forces entered Ukrainian territory Friday, and warned "there will be costs" for any military action.
“Any violation of Ukraine's sovereignty and territorial integrity would be deeply destabilizing,” Obama said from the White House, “Which is not in the interest of Ukraine, Russia or Europe. It would represent a profound interference in matters that must be determined by the Ukrainian people.”
Hours after Obama's address, the State Department issued a travel alert that warned U.S. citizens to avoid non-essential travel to Ukraine "due to the potential for instability."
The Russian forces entered the Crimea region of Ukraine by aircraft, U.S. officials confirmed to NBC News. A spokesman for the Ukranian border service numbered the planes arriving in Crimea at eight, according to the Associated Press.
“Astakhov [the spokesman] says the people in the planes refused to identify themselves and waved off customs officials, saying they didn't require their services,” the AP reported.
U.S. Ambassador Samantha Power made a similar statement after a U.N. Security Council meeting, saying the body is “gravely disturbed” by the reports. She called on Russia “to pull back the military forces that are being built up in the region” and “allow the Ukrainian people the opportunity to pursue their own government.”
Vice President Joe Biden spoke with Ukrainian Prime Minister Arseniy Yatsenyuk Friday, the White House said in a statement, to reaffirm the U.S.'s "strong support for the new government and our commitment to the sovereignty, territorial integrity, and democratic future of Ukraine."
Ukraine’s ambassador to the U.N., Yuriy Sergeyev, accused Russia of violating a military treaty between the two countries – which Russia’s U.N. ambassador, Vitaliy Churkin, denied. Sergeyev pledged that Ukraine would defend its territorial integrity.
Secretary of State John Kerry relayed a conversation with his Russian counterpart, Sergey Lavrov, Friday morning in which Lavrov said Russia would not cross the line in Ukraine.
"We would overwhelmingly stress today that we urge all parties -- all parties; that includes the new interim technical government, rightists, oppositionists and others, anybody in the street who is armed -- we urge all parties to avoid any steps that could be misinterpreted or lead to miscalculation or do anything other than to work to bring that peace and stability and peaceful transition within the governing process within Ukraine," Kerry said.
The country has been locked in violent civil conflict for weeks, sparked by President Viktor Yanukovych’s decision in November to forgo a European Union trade agreement in favor of an alliance with Russia. Ousted from office, Yanukovich fled to Russia, claiming that he was “not overthrown,” but was seeking protection against threats on his life, and that he remains the legitimate leader of Ukraine’s 45 million citizens.
More than half the population in Crimea is ethnic Russian, and about a quarter are Ukrainian. The territory was ceded to Ukraine by the Soviet Union in 1954.