Yemen's Houthi rebels must stop their attacks on ports as it is impacting the distribution of much-needed resources across the country, the US State Department said in a statement on Monday, as envoy Tim Lenderking arrived in the region.
Mr Lenderking arrived in Oman on Sunday and will travel to Saudi Arabia to support ongoing peace efforts.
"We call on the Houthis to immediately cease their attacks on Yemeni ports, which are disrupting the flow of much-needed resources and exacerbating suffering across Yemen," said the statement.
"Such attacks only risk plunging Yemenis into another pointless cycle of violence and suffering."
Washington said the Houthis must be reminded at this critical time "that Yemenis are calling for peace, not a return to war".
The visit by Mr Lenderking will be his second this month. He also visited the UAE over the UN-backed truce that failed to renew in October.
"We urge the Houthis to instead seize this opportunity for peace, co-operate with the UN, and accept that the only path forward to ending eight years of destructive war is through a negotiated, inclusive Yemeni-led political settlement," said the department.
The Iran-backed rebels rejected efforts by the UN's special envoy for Yemen, Hans Grundberg, to extend the ceasefire with the internationally-recognised government for a further six months.
Mr Grundberg also proposed broadening the scope of the agreement.
"The environment created by the UN-mediated truce presents the best opportunity Yemen has had for peace in several years," said the department.
The Iran-backed Houthis stormed the capital, Sanaa, in 2014, ousting the government and triggering a civil war that has created one of the world's worst humanitarian crises.
