Watch: Biden participates in NATO summit session

President Biden delivered remarks Wednesday during the NATO summit that he's hosting in Washington, D.C.

President Biden’s fitness for office will be put to the test this week during the summit, a high-stakes endurance test that gives the president an opportunity to push back on critics saying he is too old for a second term.

But the frantic debate over Biden’s future — as he tries to contain the fallout from his alarming debate performance last month — risks overshadowing an event aimed at projecting strength against threats from Russia and China. 

Watch the video above.