U.S. President Donald Trump on Friday called for improved relations between Japan and South Korea, saying heightened tensions between the two countries put the United States in a "bad position."

"South Korea and Japan are fighting all the time. They've got to get along because it puts us in a bad position," Trump told reporters at the White House. "They're supposed to be allies."

Trump made the remarks as ties between the key U.S. allies have sunk to the lowest level in years amid disputes over wartime history and trade policy.