The UN envoy for Yemen said Monday he will immediately return to the region to try to clinch a peace deal in the coming weeks, even though both sides have rejected his proposals.
"The ball is in the court of the Yemeni parties," Ismail Ould Cheikh Ahmed told the Security Council which met to discuss the 19-month war in Yemen.
The council is seeking to turn up the pressure on both the Iran-backed Huthi rebels and the Saudi-backed government to end the war that has killed thousands and brought the country to its knees.
"What are the parties waiting for to sign a political agreement? Have they not understood that there are no winners in wars?" asked the envoy.
Ould Cheikh Ahmed has presented a roadmap to the Huthi rebels and their allies and the Yemeni government to revive political talks, but he acknowledged to the council that his proposals had been rejected.
The plan calls for the appointment of a new vice president and the formation of a national unity government that will oversee a transition leading to elections.
Under the roadmap, the Huthis would withdraw from Sanaa, Hodeidah and Taez and hand over their weapons in a process carried out in parallel with the new political arrangements.
Yemen's President Abedrabbo Mansour Hadi has rejected the UN peace proposal, saying it "rewards the putschists" who seized power in Sanaa, while the rebels said the roadmap had "fundamental flaws."
One of the poorest countries in the Arab world, Yemen slid deeper into chaos when the Saudi-led coalition launched military operations in March 2015 in support of Hadi and to push back the Huthi rebels.
International alarm has been growing over air strikes that have hit civilian targets including a community hall where more than 140 people died this month while attending a funeral.
Ould Cheikh Ahmed said he would return to the region immediately after his report to the council and that his roadmap "should allow a comprehensive settlement in the coming weeks if the parties engage in good faith."
The Mauritanian diplomat has led negotiations in Yemen since April 2015 and brokered a series of ceasefires that were often violated and failed to generate momentum towards a peace deal.
Almost 6,900 people have been killed in the war -- more than half of them civilians -- while another three million are displaced and millions more need food aid.
UN aid chief Stephen O'Brien told the council that the humanitarian crisis was worsening, with 80 percent of the population in need of food.
"Yemen is one step away from famine," he said. Over two million people are malnourished including 370,000 children who face severe malnutrition.
Cholera is spreading, with 61 confirmed cases and more than 1,700 suspected cases, said O'Brien, the UN under-secretary general for humanitarian affairs.
He urged Saudi Arabia to allow commercial flights to resume to Sanaa to allow students to pursue their studies abroad and Yemeni patients to obtain treatment.
"It is within their power, their choice to permit this," he said of Riyadh.
O'Brien appealed to donors to help rebuild the port of Hodeidah, which was damaged by air strikes, describing it as "the lifeline of the country" which is almost entirely reliant on imports.