The US has blamed Yemen's Iran-backed Houthi rebels for the failure of a ceasefire to take hold in the country and accused them of not taking other steps toward ending the brutal conflict.
"While there are numerous problematic actors inside of Yemen, the Houthis bear major responsibility for refusing to engage meaningfully on a ceasefire and to take steps to resolve a nearly seven-year conflict that has brought unimaginable suffering to the Yemeni people," the State Department said on Friday.
The statement was issued after the US special envoy for Yemen, Tim Lenderking, returned on Thursday from a trip to Saudi Arabia, Oman, the UAE and Jordan. He discussed the humanitarian and economic crisis in Yemen with government officials, Yemenis and international partners, the State Department said.
US President Joe Biden has made Yemen a priority since taking office in January, and appointed Mr Lenderking to help revive stalled UN peace efforts.
After Mr Lenderking returned from a visit last month, the State Department accused the Houthis of worsening Yemen's humanitarian crisis by attacking Marib, the last northern stronghold of the government.
The situation has not changed.
"The Houthis continue a devastating offensive on Marib that is condemned by the international community and leaves the Houthis increasingly isolated," the State Department said.
Mr Lenderking talked to Yemenis about strengthening "inclusive processes" that could help citizens discuss the country's future and increase efforts towards peace, it said.
Yemen has been embroiled in a civil war since 2014, when the Iranian-backed rebels swept across much of the north and seized the capital, Sanaa, forcing the internationally recognised government into exile.
A Saudi-led coalition entered the conflict the following year on the side of the government. The war has killed more than 130,000 people and spawned the world’s worst humanitarian crisis.
The State Department said Mr Lenderking co-ordinated his efforts closely with the UN special envoy for Yemen Martin Griffiths, who held video talks recently with Houthi leader Abdelmalik Houthi.
Mr Griffiths expressed frustration that his efforts to achieve a ceasefire have been derailed by warring parties seeking gains on the battlefield. He urged the sides to seize the “considerable regional and international support” for the UN peace plan.
Mr Lenderking’s rebuke to the Houthis came as the UN Security Council criticised the rebels for delaying a technical assessment of an oil tanker moored off the war-torn country’s coast loaded with more than one million barrels of crude oil.
Reena Ghelani, a senior UN aid official, told the Security Council on Thursday that the long-planned expedition to the FSO Safer was running out of funding because the Houthis had delayed the start of the mission.
The rebels, who control the coastline nearby, repeatedly refused to grant access to the ship before approving the UN mission in November, only to renege later.
There are fears that the tanker could rupture and spill its load into the sea, causing an environental disaster.