Russian President Vladimir Putin has signed a treaty to make Ukraine's Crimea part of Russia, angering the United States and European Union.
Mr. Putin Tuesday signed the document with the prime minister of Crimea's regional government , the speaker of its parliament, and the mayor of the city of Sevastopol , where Russia's Black Sea fleet is based.
Earlier, Mr. Putin told the Russian parliament that Crimea has always been an "inalienable" part of Russia. He said Sunday's referendum, in which Crimean voters decided in favor of joining Russia, complied with democratic and international norms.
White House spokesman Jay Carney condemned Russia's latest move, saying it clearly violates international law and disregards Ukraine's constitution and sovereignty. Carney said the international community will not recognize Crimea as part of Russia
Also Tuesday, Russian and Ukrainian news media quoted a Ukrainian military spokesman as saying Russian forces attacked Ukrainian troops at a base in Crimea's main city, Simferopol, killing one serviceman.
Britain has suspended military cooperation with Russia in light of the dispute over Crimea. A planned naval exercise is canceled and a British Royal Navy ship visit to Russia is suspended.
Crimean officials say the final ballot count from Sunday's referendum shows 97 percent of voters favored independence from Ukraine.
Senior White House officials say they have "concrete evidence" that some ballots were marked before the vote.
In his speech to parliament Tuesday, Mr. Putin insisted Russia has always respected Ukraine's territorial integrity and neither wants to nor needs to "partition" Ukraine.
He criticized Soviet leader Nikita Khrushchev's decision to transfer Crimea from Russia to Ukraine in 1954. When Crimea ended up as part of independent Ukraine after the fall of the Soviet Union in 1991, Mr. Putin said Russia felt it was not simply "robbed," but "plundered."
Mr. Putin also said that after the Russian Revolution of 1917, "significant historical territory" of southern Russia, including "present-day southeastern Ukraine," was included in the Ukrainian republic of the Soviet Union "without regard to the ethnic composition of the population."
The Russian leader described last month's ouster of Ukraine's pro-Russian president, Viktor Yanukovych, as a coup by "nationalists, neo-Nazis, Russophobes and anti-Semites."
Ukrainian Prime Minister Arseniy Yatsenyuk said Tuesday that his country's law enforcement agencies have "convincing evidence" Russia's special services are involved in unrest in eastern Ukraine.
Separately, Mr. Yatsenyuk told CNN there is "a strong possibility" of a Russian invasion of Ukraine.