The Trump administration has asked every member of the US Senate to meet at the White House on Wednesday for a briefing on North Korea, in a rare and unusual move, amid mounting tensions with Pyongyang.

All 100 senators have been asked to attend the Wednesday briefing, which will be conducted by Secretary of State Rex Tillerson, Secretary of Defense Jim Mattis, Director of National Intelligence Dan Coats, and Chairman of the Joint Chiefs of Staff General Joseph Dunford, White House spokesman Sean Spicer said on Monday.