During a press conference on Monday in advance of President Obama's final foreign trip in office, he said that in his discussion with president-elect Donald Trump, that the latter expressed interest in preserving the North Atlantic Treaty Organization (NATO). "In my conversation with the president-elect, he expressed a great interest in maintaining our strategic relationships," Obama said during the press conference in which he emphasized the importance of the transition of power. "So, one of the messages I will be able to deliver is his commitment to NATO and the Trans-Atlantic Alliance. I think that's one of the most important functions I can serve at this stage during this trip is to let them know that there is no weakening of resolve when it comes to America's commitment to maintaining a strong and robust NATO relationship and a recognition that those alliances aren't just good for Europe, they're good for the United States. And they're vital for the world."

Trump has frequently criticized NATO during his presidential campaign and in a March interview said "I think NATO may be obsolete," and he would "certainly look at" getting rid of it.

—Gideon Resnick