U.S. MOVE MAY STYMIE PEACE: U.N.

The outgoing U.S. administration is to designate Yemen's Houthi movement as a foreign terrorist organization, a move the United Nations warned could have serious repercussions for peace talks and efforts to combat the world's largest humanitarian crisis.

A leader of the Iranian-aligned group, which has been battling a Saudiled coalition in Yemen since 2015 in a war widely seen as a proxy conflict between Iran and Saudi Arabia, said it reserved the right to respond.

Secretary of State Mike Pompeo announced the move, which will include sanctions against the movement and three of its leaders, late on Sunday. It will come into effect on Jan. 19, the Trump administration's last day in office.

“It's clear that the decision is likely to have serious humanitarian and political repercussions,” UN spokesman Stephane Dujarric said Monday, urging Washington to ensure aid is not disrupted.

The U.S. administration has been piling on sanctions related to Iran in recent weeks.