U.S. Secretary of State Mike Pompeo says he's "very hopeful" that progress can be made toward ending Yemen's war.

America's top diplomat said he would speak later Tuesday with U.N. envoy for Yemen Martin Griffiths, who has been trying to bridge gaps between its Saudi-backed, internationally recognized government and Iran-aligned Shiite rebels known as Houthis.

He spoke Tuesday by videoconference to the World Economic Forum in Davos, after President Donald Trump cancelled plans for a U.S. delegation to attend because of the government shutdown.

In another session, David Miliband, who heads the International Rescue Committee, said the conflict in Yemen was emblematic of the "rise of the age of impunity" where belligerents "can commit crimes and not be held accountable."

Yemen, he said, is "often described as a tragedy, but it in fact is better described as a series of crimes."

The United Nations says Yemen is facing the world's biggest humanitarian crisis.

AFP.