The United States and Britain are expressing hope that a cease-fire can be reached in Yemen in the coming days.

U.S. Secretary of State John Kerry says mediation is ongoing involving Yemen's exiled, internationally recognized government and the Houthi rebels who control much of the country.

Kerry says: "This is the time to implement a cease-fire unconditionally and then move to the negotiating table."

His message Sunday was supported by British Foreign Secretary Boris Johnson and the U.N. envoy to Yemen, Ismail Ould Cheikh Ahmed.

Kerry says they want the truce "''as rapidly as possible, meaning Monday, Tuesday."

Their meeting in London also included the foreign minister of Saudi Arabia, which has led a military coalition against the Houthis.