Lenderking said all ports and airports in Yemen should be opened to ease a humanitarian crisis Riyadh had in March proposed a nationwide ceasefire and the reopening of air and sea links to bolster efforts to end the conflict in the country DUBAI: The United States is imposing sanctions on two Houthi military officials leading the Iran-backed militia"s offensive to seize Yemen"s gas-rich Marib region, US Special Envoy on Yemen said on Thursday. Tim Lenderking, who has been pushing for a ceasefire between the Houthis and the Arab coalition, also told a virtual media briefing that all ports and airports in Yemen should be opened to ease a humanitarian crisis. Riyadh had in March proposed a nationwide ceasefire and the reopening of air and sea links to bolster efforts to end the conflict in the country. But the initiative has been stuck since the Houthis made a series of counter-proposals, including fully lifting the coalition"s blockade before any truce deal. Lenderking said the United States would on Thursday impose sanctions on the head of the general staff leading the Houthi offensive in Marib, Mohamad Abdulkarim Al-Gamali, and on a prominent leader of Houthi forces assigned to the advance on Marib, Yousuf Al-Madani. "If there were no offensive, if there were commitment to peace, if the parties are all showing up to deal constructively with the UN envoy there would be no need for designations," he said. The Houthi offensive in Marib was going nowhere and was only endangering more than 1 million people, he said, while stressing that all economic arteries, including ports and airports. He said Washington wants a long-term solution that goes beyond a ceasefire, which the envoy said was the only way Yemenis would get the humanitarian relief they require.