MAFRA, Portugal — President Vladimir Putin on Friday evoked one of the most dangerous confrontations of the Cold War to highlight Russian opposition to a proposed U.S. 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 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.

Putin used a news conference at the summit's conclusion to reiterate Russia's stalwart opposition to U.S. 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,"' Putin said, using the Russian term for the Cuban missile crisis.