US Secretary of State Mike Pompeo said UN-led peace negotiations must resume in November and called for a cessation of hostilities in Yemen.
Mr Pompeo's statement on Tuesday coincided with the deployment by the Arab coalition of 10,000 additional troops to the Houthi-held city of Hodeidah, ahead of a new offensive.
The port city is the entry point for more than 70 per cent of imports to the impoverished country.
"The time is now for the cessation of hostilities, including missile and UAV (drone) strikes from Houthi-controlled areas into the Kingdom of Saudi Arabia and the United Arab Emirates," Mr Pompeo said in a statement. "Subsequently, coalition air strikes must cease in all populated areas in Yemen."
On Wednesday Omar Saleh, an officer in the Yemeni military, told The National that "thousands of Yemeni soldiers from the Sudanese forces ... were deployed along with thousands of Yemeni fighters."
A separate military source in the Al Amalikah brigades said the deployment includes UAE soldiers, armoured vehicles and heavy weapons.
Meanwhile, inside Hodeidah, civilians ready themselves for a renewed offensive.
"We are patiently waiting for the resistance to storm the city and kick the Houthi thugs out," Nashwan Mohammed told The National. "We have suffered a lot, we hardly get food and we keep struggling to get a little polluted water as most of the water network in the city has been cut for more than four months because of the Houthis who kept digging trenches on the water pipes causing big damage in it."
For months residents have been caught amid heavy fighting between Iran-backed Houthis and Yemeni government forces, backed by the Arab coalition.
Hundreds of thousands have been displaced, with most too scared to return and living in displaced people's camps instead. But not everyone has had the opportunity to escape.
"The residents in the middle of the city have been suffering too much, the Houthis blocked all the roads leading to them, [there is] one road only which is accessible for them," Abdulwahab Shoubail, a media activist from Hodeidah who was recently displaced to Aden, said.
Houthi rebels have for the past 10 days been stationing fighters on rooftops of buildings in Hodeidah city, the Agence France-Presse reported, citing government military officials. Pentagon chief Jim Mattis said the US had been watching the conflict "for long enough," adding that Saudi Arabia and the United Arab Emirates are ready for talks.
Speaking at the US Institute of Peace in Washington on Tuesday Mr Mattis said US support is based primarily on teaching the Saudi air force to improve targeting and to not drop bombs when there is any doubt of what they might hit. In addition, Mr Mattis said the ceasefire should be based on a pullback of Houthi rebels from the border and a ceasefire, and the parties must come together to end the war.
"That will permit the special envoy Martin Griffiths... to get them together in Sweden and end this war. That is the only way we are going to really solve this," he said.
Last month, UN-led peace talks failed to take off after Houthi rebels refused to fly to Geneva.
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 Houthis in 2015.
Nearly 10,000 people have since been killed and millions are on the brink of famine as aid agencies are struggling to find a way to ensure relief reaches those in need, especially in Houthi-held areas.
Also on Tuesday the newly appointed Yemeni Prime Minister Maeen Abdulmalik arrived from Saudi Arabia to Aden, where he is expected to base himself.
Mr Abdulmalik said he would focus on tackling the country's economy, construction and cooperation with the government, state-owned agency Saba reported. Upon his arrival, Mr Abdulmalik met with UAE Minister of State for International Cooperation Reem Al Hashimy to discuss rehabilitation in the country's liberated areas.
After nearly four years of war, Yemen's health sector has also been badly battered, while a struggle over the central bank has left public sector salaries for doctors and sanitation workers unpaid.
"All of the nurses and doctors left ... They hadn't been paid for a year," said the head of the Norwegian Refugee Council Jan Egeland of a hospital ward he visited last year.
Mr Egeland said non-payment of medical staff was having a "devastating effect" on the delivery of healthcare as Yemen's cholera outbreak - the worst in the world - is worsening.
Roughly 10,000 suspected cases are reported per week, according to the World Health Organization - double the average rate for the first eight months of the year.
A total of 1.2 million suspected cases have been reported, with more than 2,500 deaths, since the epidemic erupted in 2017.
In addition Mr Egeland said it was vital to stem the collapse of Yemen's education system, with about one million children displaced. "Children out of school are extremely vulnerable for sexual violence, violence in general (and) for recruitment via extremist groups," he said.