The war has killed more than 10,000 people, displaced three million and unleashed the world's most urgent humanitarian crisis in the impoverished Arab state which is struggling with a starvation and cholera epidemic, according to the United Nations.
Oxfam's Yemen Country Director, Mohsin Siddiquey, said aid groups were "moving very fast" to evacuate staff in Hodeidah before the imminently expected attack has a "catastrophic impact". "I hope that it will be possible to avoid a battle for Hodeidah".
Correspondence sent from European donor governments to aid groups in Yemen on Saturday warned that "a military assault now looks imminent", according to the text of the correspondence seen by Reuters.
The lawmakers also want more transparency about the US role in Yemen, The Hill reported.
The statement by Secretary of State Mike Pompeo stopped short of warning the Saudi and UAE-led coalition against besieging the key city.
The United Nations pulled all of its worldwide staff out of Hodeida early Monday morning.
Malki also commented on the Houthis' launch of four ballistic missiles towards Saudi Arabia during the past two months, adding that one of these missiles fell in Yemen.
The United Nations has warned that up to 250,000 people are at risk if the coalition moves ahead with an all-out offensive to take over the port, which is a major entry point for commercial supplies and aid.
Griffiths is working on a peace plan that involves the Houthi rebels giving up their ballistic missile arsenal in return for an end to Saudi-led air strikes and a political roadmap, ultimately paving the way for a transition out of the crisis. He is due to brief the U.N. Security Council later this month.
Saudi Arabia, the United Arab Emirates and other allies intervened in Yemen in 2015 to push back the rebels and restore the internationally-recognised government to power after the Huthis ousted it from swathes of the country including the capital Sanaa.
The council met behind closed doors to hear United Nations envoy Martin Griffiths report on his diplomatic efforts to keep the rebel-held port of Hodeidah open to shipments of aid and commercial goods.
UN Secretary General Antonio Guterres said there are "intense negotiations" and his Yemen envoy is involved in shuttle diplomacy to stave off the attack. "We have dozens of United Nations staff still in Hudeidah", Lowcock said.