US Secretary of State Mike Pompeo has called for an end to the fighting in Yemen.
Pompeo said missile strikes by the Iran-allied Houthi rebels against Saudi Arabia and the United Arab Emirates should stop, and that the Saudi-led coalition must stop air strikes in all populated areas.
Pompeo added that UN-led negotiations to bring the civil war to an end should begin next month.
Pompeo's call was earlier voiced by US Secretary of Defence Jim Mattis even as the Saudi-led military coalition sent more than 10,000 new troops toward a vital rebel-held port city ahead of a new assault.
Mattis said the US had been watching the conflict "for long enough", adding that Saudi Arabia and the United Arab Emirates, which are in a US-backed coalition fighting Shiite Huthi rebels, are ready for talks.
"We have got to move toward a peace effort here, and we can't say we are going to do it some time in the future," Mattis said at the US Institute of Peace in Washington.
"We need to be doing this in the next 30 days."
He said the US is calling for all warring parties to meet with United Nations special envoy Martin Griffiths in Sweden in November and "come to a solution."
US-Saudi ties have cooled in recent weeks after the murder of journalist Jamal Khashoggi, a prominent critic of the conservative kingdom, that has also tarnished the image of Crown Prince Mohammed bin Salman.
Saudi Arabia and its allies intervened in the conflict between embattled Yemeni President Abedrabbo Mansour Hadi, whose government is recognised by the United Nations, and the Huthis in 2015.
Nearly 10,000 people have since been killed and the country now stands at the brink of famine, with more than 22 million Yemenis — three-quarters of the population — in need of humanitarian assistance.