Hailing ties with Tokyo as the closest ever, U.S. President Donald Trump on Monday emphasized America's "solidarity" with Japan against "the North Korean menace," but at the same time made no secret of his dissatisfaction with what he considers an unfair trade relationship with its top Asian ally.

Trump's comment came as he stood together with Prime Minister Shinzo Abe at a joint news conference designed to showcase what the two leaders touted as an unprecedented level of Japan-U.S. solidarity.

Trump, who was in Japan on the first stop of his five-nation trip to Asia, was scheduled to finish his three-day stay in Tokyo on Tuesday morning when he flies to his next destination, South Korea.