MOSCOW -- With a historic sweep of his pen, President Vladimir Putin signed a treaty Tuesday to annex Crimea, describing the move as correcting past injustice and a necessary response to what he called Western encroachment upon Russia's vital interests.
In an emotional 40-minute speech that was televised live from the Kremlin, Putin said "in people's hearts and minds, Crimea has always been an integral part of Russia."
He dismissed Western criticism of Sunday's Crimean referendum - in which residents of the strategic Black Sea peninsula overwhelmingly backed breaking off from Ukraine and joining Russia - as a manifestation of the West's double standards.
At the same time, the Russian leader said his nation didn't want to move into other regions of Ukraine, saying "we don't want division of Ukraine."
Thousands of Russian troops have been massed along Ukraine's eastern border for the last few weeks - Russia says that was for military training while the U.S. and Europe view the troops as an intimidation tactic.
Putin argued that months of protests in Ukrainian capital that prompted President Viktor Yanukovych to flee to Russia had been instigated by the West in order to weaken Russia. He cast the new Ukrainian government as illegitimate, driven by radical "nationalists, neo-Nazis, Russophobes and anti-Semites."
Following the speech before lawmakers and top officials, Putin and Crimean officials signed a treaty for the region to join Russia.
The treaty will have to be endorsed by Russia's Constitutional Court and ratified by both houses of parliament, but Valentina Matviyenko, the speaker of upper house of Russian parliament, said the procedure could be completed by the end of the week.
In his speech at the Kremlin's white-and-gold St. George hall, Putin said the rights of ethnic Russians in Ukraine had been abused by the new Ukrainian government. He insisted that Crimea's vote Sunday to join Russia was in line with international law and reflected its right for self-determination.
Putin's speech came just hours after he approved a draft bill for the annexation of Crimea, a key move in a flurry of steps to formally take over the Black Sea peninsula.
To back his claim that Crimea's vote was in line with international law, Putin pointed to Kosovo's independence bid from Serbia - supported by the West and opposed by Russia - and said that Crimea's secession from Ukraine repeats Ukraine's own secession from the Soviet Union in 1991.
He denied Western accusations that Russia invaded Crimea prior to the referendum, saying Russian troops were sent there in line with a treaty with Ukraine that allows Russia to have up to 25,000 troops at its Black Sea Fleet base in Crimea.
Putin had previously warned that he would be ready to use "all means" to protect Russian speakers in eastern Ukraine, and Russia has built up its forces alongside the border between the two countries, raising fears of an invasion.
Ukraine's Prime Minister Arseniy Yatsenyuk said in a televised statement that Ukrainian law-enforcement agencies have gathered "convincing evidence of the participation of Russian special services in organizing unrest in the east of our country."
The hastily called Crimean vote was held just two weeks after Russian troops had overtaken the Black Sea peninsula, blockading Ukrainian soldiers at their bases. The West and Ukraine described the referendum as illegitimate and being held at gunpoint. But residents on the peninsula voted overwhelmingly to join Russia.
Crimea had been part of Russia since the 18th century until Soviet leader Nikita Khrushchev transferred it to Ukraine in 1954. Both Russians and Crimea's majority ethnic Russian population see annexation as correcting a historic insult.
The United States and the European Union on Monday announced asset freezes and other sanctions against Russian and Ukrainian officials involved in the Crimean crisis. President Barack Obama warned that more would come if Russia didn't stop interfering in Ukraine.
Earlier in the day, France's Foreign Minister Laurent Fabius said on Europe-1 radio leaders of the Group of Eight world powers "decided to suspend Russia's participation and it is envisaged that all the other countries, the seven leading countries, will unite without Russia."
The other seven members of the group had already suspended preparations for a G-8 summit that Russia is scheduled to host in June in Sochi.
In his speech, Putin made it clear that Russia wouldn't be deterred by Western sanctions, and asked China and India for their support.
The Russian State Duma, the lower chamber of parliament, on Tuesday unanimously passed a resolution condemning U.S. sanctions targeting Russian officials including members of the chamber. The chamber challenged Obama to extend the sanctions to all the 353 deputies who voted for Tuesday's resolution, suggesting that being targeted was a badge of honor. Eighty-eight deputies left the house before the vote.
Putin found support even in unusual places. Former Soviet President Mikhail Gorbachev hailed Crimea's vote to join Russia as a "happy event." In remarks Tuesday by online newspaper Slon.ru, he said Crimea's vote offered residents the freedom of choice and showed that "people really wanted to return to Russia."
Gorbachev added that the referendum set an example for people in Ukraine's Russian-speaking eastern region, who he said also should decide their fate.
Many in Crimea's ethnic Tatar minority were wary of the referendum, fearing that Crimea's break-off from Ukraine would set off violence against them. Crimean Deputy Prime Minister Rustam Temirgaliyev seemed to confirm those fears, saying in remarks carried by the RIA Novosti news agency that the government would ask Tatars to "vacate" some of the lands they "illegally" occupy so authorities can use them for "social needs."
But Putin on Tuesday vowed to protect the rights of Crimean Tatars and keep their language as one of Crimea's official tongues, along with Russian and Ukrainian.
Ukraine's political turmoil has become Europe's most severe security crisis in years. It began in November with a wave of protests after Yanukovych ditched a deal with the 28-nation European Union in favor of closer ties and a bailout loan from Russia. The protests went on for months, prompting Yanukovych to flee to Russia in late February and leading to the installation of a new government.
Jim Heintz in Kiev, Angela Charlton in Paris and Vladimir Isachenkov in Moscow contributed to this report.