President Donald Trump met with Ukrainian leader Volodymyr Zelenskyy on the sidelines of the NATO summit Wednesday and suggested that increased spending by the trans-Atlantic alliance could help prevent future Russian aggression against its neighbors.

Following his closed-door meeting with Ukrainian President Volodymyr Zelenskyy at the NATO Summit on Wednesday, President Donald Trump didn't rule out sending Ukraine monetary and defense aid as he voiced frustrations with Russian President Vladimir Putin.

U.S. President Donald Trump has said President Volodymyr Zelensky is a "nice guy" ahead of a meeting at NATO summit in The Hague on June 25, saying they will be "discussing his difficulties." The White House confirmed the meeting on June 24 but did not release further details.