Visiting U.S. Defense Secretary James Mattis met with Prime Minister Shinzo Abe in Tokyo on Friday, reaffirming Washington's commitment to the military alliance with Japan as global concern grows over the policies of U.S. President Donald Trump.

At the outset of the meeting, Mattis told Abe that "we stand firmly, 100 percent for" the alliance with Japan in light of the military threat from North Korea.

"I want to make certain that Article 5 of our mutual defense treaty is understood to be real to us today, as it was a year ago, five years ago" and ten years from now as well, Mattis told Abe.