2,000 Armed Russian Troops Reportedly Enter Ukraine; Obama Delivers Brief Reaction (Update: 'Happy Hour')

AFP reports that the Russians have crossed into Ukraine's Crimean peninsula. Ukraine is accusing Russia of "armed invasion."

"Thirteen Russian aircraft landed at the airport of Gvardeyskoye (near Simferopol) with 150 people in each one," Sergiy Kunitsyn, the Ukrainian president's special representive in Crimea, told the local ATR television channel, adding the air space had been closed. It was not immediately clear if Russia had the right to use the base or send additional troops there under its agreements with Ukraine.

This follows reports that Russian troops have been on the streets in Crimea, and follows by a day reports that unidentified, masked, professional gunmen had seized the parliament building in Simferopol, Crimea's capital, and raised the Russian flag.

President Obama offered a brief statement on the situation, from the White House. After noting the cultural and military ties between Ukraine and Russia, he said: "But any violation of Ukraine's sovereignty and territorial integrity would be deeply destabilizing, which is not in the interests of Ukraine, Russia, or Europe. It would represent a profound interference in matters that must be determined by the Ukrainian people. It would be a clear violation if Russia's commitment to respect the independence, sovereignty, and borders of Ukraine, and of international laws."

Obama noted that any Russian incursion coming so close to the end of the Sochi Olympics "would invite the condemnation of nations around the world. And indeed, the United States will stand with the international community in affirming that there will be costs for any military intervention in Ukraine." Obama added that "the events of the past several months" remind the world "how difficult democracy can be in a country with deep divisions."

Obama said that Vice President Joe Biden had spoken with Ukraine's prime minister. He took no questions from the media.

Update: Video of the president's remarks.

Update: CNN reports that a US official says the Russian troop incursion was an "uncontested arrival."

Update: Russian chess champion and long-time Putin critic Garry Kasparov:

Update: The United States signed a security treaty with Ukraine in 1994, in exchange for that country giving up its USSR-era nuclear weapons.

Update: After delivering his brief remarks, President Obama went to a Democratic Party gathering.


Update: While the president was enjoying happy hour, US Ambassador to the UN Samantha Power delivered a stronger statement. According to Power's prepared remarks, the US is calling for Russia to "pull back" from Crimea.