British foreign secretary Jeremy Hunt said on Sunday that a peace process in Yemen's main port city "could be dead within weeks" without more committed effort from both sides.

The agreement to implement a troop withdrawal in Hodeidah, a lifeline for millions facing famine, by Jan. 7 was intended to clear the way for wider negotiations to end the four-year war but progress has been slow.

"We are now in last chance saloon for the Stockholm peace process," Hunt said in a statement during a visit to Yemen.

"The process could be dead within weeks if we do not see both sides sticking to their commitments in Stockholm."