U.S. Secretary of Defense Jim Mattis has held trilateral talks with Japan and South Korea, to discuss North Korea’s missile programme.
Mattis’ visit comes just weeks before Donald Trump’s first visit to Asia as president.
Japanese defence minister said during the meeting that the threat from Pyongyang has grown to a serious and critical level.
North Korea is working to develop a nuclear-tipped missile capable of striking the U.S. mainland.
It has so far ignored all calls to rein in its weapons programmes which it conducts in defiance of U.N. Security Council resolutions.