MAFRA, Portugal — President Putin today evoked one of the most dangerous confrontations of the Cold War to highlight Russian opposition to a proposed American missile defense system in Europe, comparing it to the Cuban missile crisis of 45 years ago.

The comments — made at the end of a summit between Russia and European Union that failed to resolve several festering disputes — were the latest in a series of belligerent statements from the assertive Mr. Putin.

Emboldened by oil- and gas-fueled economic clout, Russia is increasingly at odds with Washington and much of Europe on issues ranging from Iran and Kosovo to energy supplies and human rights.

Mr. Putin used a news conference at the summit’s conclusion to reiterate Russia’s stalwart opposition to American plans to put elements of a missile defense system in the former Soviet bloc countries of Poland and the Czech Republic — both of which are now NATO members.

“Analogous actions by the Soviet Union, when it deployed missiles in Cuba, prompted the ‘Caribbean crisis,'” Mr. Putin said, using the Russian term for the Cuban missile crisis.

“For us the situation is technologically very similar. We have withdrawn the remains of our bases from Vietnam, from Cuba, and have liquidated everything there, while at our borders, such threats against our country are being created,” he said.

The October 1962 crisis erupted when President John F. Kennedy demanded that Soviet leader Nikita S. Khrushchev remove his country’s nuclear missiles from Cuba because they could have been used to launch a close-range attack on America. The Americans imposed a naval blockade on Cuba and the world teetered on the edge of war before the Soviets backed down.

Mr. Putin also suggested that the tension was much lower than in 1962 because America and Russia are now “partners,” not Cold War enemies. His relationship with President Bush, Mr. Putin said, helps solve problems, calling him a “personal friend.”

The Russian leader said there has been no concrete American response to his counterproposals for cooperation on missile defense, but added that America is now listening to Russia’s concerns about its plans and seeking to address them.

In Washington, a White House press secretary, Dana Perino, underscored those remarks rather than the Cuban missile crisis analogy, saying “there’s no way you could walk away without thinking that he thinks that we can work together.”

The American plan is part of a wider missile shield involving defenses in California and Alaska which America says are to defend against any long-range missile attack from countries such as North Korea or Iran.

Russia strongly opposes the idea, saying Iran is decades away from developing missile technology that could threaten Europe or North America, and it says the American bases are aimed at spying on Russian facilities and undermining Russia’s missile deterrent force.

A State Department spokesman, Sean McCormack, told reporters there were “clear historical differences between our plans to deploy a defensive missile system designed to protect against launch of missiles from rogue states, such as Iran, and the offensive nuclear-tipped capability of the missiles that were being installed in Cuba back in the 1960s.”

“I don’t think that they are historically analogous in any way, shape or form,” he said.