* Putin vows to defend compatriots in Ukraine
* Says Ukraine suffered armed seizure of power
* Russia will act against "lawlessness"
By Alexei Anishchuk
NOVO-OGARYOVO, Russia, March 4 (Reuters) - President Vladimir Putin on Tuesday defended Russia's right to send troops into Ukraine to protect compatriots living in "terror", but said he would only use force as a last resort.
Breaking his silence since the removal of Russian-backed President Viktor Yanukovich from power, the former KGB spy defended a strategy that has drawn charges from the West that events in Ukraine have exposed his Cold War-style thinking.
Looking relaxed, he tried to turn the tables on the West, wondering out loud what would result from Washington's latest experiment in democracy with "lab rats" in Ukraine.
"There can be only one assessment of what happened in Kiev, in Ukraine in general. This was an unconstitutional coup and the armed seizure of power. No one argues with this. Who can argue with it?" Putin asked a small group of reporters at a state residence near Moscow.
"This is the last resort. We believe, have believed and will believe, that Ukraine is not only our closest neighbour but a brotherly republic."
Fielding questions for more than a hour, the 61-year-old made his case for Russia's position on Ukraine, doing little to bridge the gulf in the understanding between the West and Moscow of what happened in Ukraine over the last week.
He denied that Russian troops had seized Ukraine's southern Crimea region, where armed men, with no insignia but bearing all the marks of their Russian origins, have taken control of all official buildings and some army bases.
Among the armed groups, however, are many servicemen from the Russian Black Sea Fleet which has a base in Crimea.
Putin also said Russia would not encourage separatist moves in Ukraine, where many people are Russian speakers and have closer ties to Russia than to the leaders in Kiev seeking stronger relations with the European Union.
Crimea's prime minister has said he will hold a referendum on the region's status later this month and that he could bring it forward from March 30.
But Putin said that if "lawlessness" spreads to the country's industrial east, Russia would be within its rights to act because it had a signed request to do so from Yanukovich, who he said was the legitimate president of Ukraine.
"Even if I take a decision to use armed force, it will be legitimate, fully corresponding to the norms of international law," he said. "And, in this case, it would also correspond to our interest in protecting the people who are closely tied to us historically, culturally, economically."
Pointing the finger of blame at the West for stirring passions in Ukraine, he said the overthrow of Yanukovich was orchestrated by "western instructors".
While it was clear many in Ukraine wanted change to rid the country of the corruption and nepotism associated with Yanukovich's rule, he said, it was not clear they wanted a new government that would not offer an equal say to all Ukrainians.
"And this is not the first time our Western partners are doing this in Ukraine. Sometimes I get the impression that across the pond, somewhere in America, staff at some laboratory are sitting there conducting experiments, like on rats, without understanding the consequences of what they are doing," he said.
He shrugged off threats from U.S. and EU officials that Russia could face sanctions over Ukraine, suggesting they had more to fear from breaking with Russia that Moscow did from such moves.
The EU is dependent on gas supplies from Russia and the United States may need Russian support in efforts to end the war in Syria and curb Iran's nuclear programme.
"We consider our approach well-founded and any threats against Russia counterproductive and harmful," he said, adding that if western countries did not want to attend a meeting of the Group of Eight most industrialised countries in Russia in June, "they don't need to".
But he said Moscow would cooperate with them to find a solution for Ukraine which he argued should be based on an EU-brokered Feb. 21 agreement that Yanukovich signed before fleeing Kiev. The ousted leader is now in Russia.
"They have supported an anti-constitutional coup and an armed seizure of power. They have declared these people legitimate and are trying to support them," he said.
"Even in this case, we are patient and ready to cooperate even, we do not want to break ties."