Mr Lenderking said Houthi military setbacks in Marib and Shabwa to pro-government forces should remind the rebels that the war will end at the negotiating table — not on the battlefield.
“Houthi recent losses in Yemen should indicate to them, and all the parties, again: there is no military solution,” Mr Lenderking told an online meeting of the US Institute of Peace, a federally funded think tank.
“When we look at the Houthi offensive in Marib, including repeated attacks on civilian areas in that city, and attacks against internally displaced persons camps, we can see that the Houthi’s Marib offensive over the last year has been the primary obstacle to peace.”
The Iran-backed Houthi rebels launched an assault in February last year to capture Marib, sweeping through the surrounding areas to reach the city’s outskirts, with the goal of cementing their hold over Yemen’s north.
The assault collapsed earlier this year when pro-government forces pushed back, retaking a significant amount of territory around the city.
As fighting intensified, the Houthis launched a string of cross-border drone and missile attacks on Saudi Arabia and the UAE.
The year-long battle over the strategic city has displaced about 100,000 people, uprooting many who had been forced to flee their elsewhere in previous bouts of conflict, the aid group Oxfam said on Tuesday.
UN figures show that Marib province is hosting about one million displaced people, mostly women and children. This is a quarter of the overall four million who have had to relocate due to the conflict. Local officials put the Marib figure at about two million.
Muhsin Siddiquey, Oxfam’s director in Yemen, said civilians had borne the brunt of violence in the offensive, noting he was “particularly worried” by reports that records are not being kept of where landmines have been planted.
The war has claimed more than 370,000 lives, directly and indirectly, the UN says, and spawned a humanitarian crisis, leaving more than 80 per cent of the population of about 30 million people needing aid.
Mr Lenderking warned of a $3.9 billion “funding gap” in this year's UN funding appeal for food, shelter and other aid for impoverished Yemenis and urged donors to “give generously as they have in the past”.