A strong and unified Europe is "good" for the United States and NATO is "absolutely vital" to U.S. interests, Barack Obama said as he kicked off his final foreign tour as U.S. president.
Obama told Greek President Prokopis Pavlopoulos in Athens on November 15 that Democratic and Republican administrations alike recognize the importance of the alliance to the transatlantic relationship.
Obama sought to assure U.S. allies that President-elect Donald Trump will honor the country's international alliances when he takes office in January.
During the campaign, Trump said he might abandon a guarantee of protection for fellow NATO countries if they had not properly fulfilled their financial obligations to the alliance.
On November 16, Obama is scheduled to give a speech about democracy and globalization in Athens before flying on to Berlin.
From Germany, Obama will travel to Peru for a summit of the Asia-Pacific Economic Cooperation forum before returning to Washington on November 19.