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Mr Lenderking was speaking before his trip to Oman for talks on the crisis that has triggered retaliatory US and British strikes on Yemen.
“The sense we have is overwhelmingly that Iran is pushing on an open door here with the Houthis, aiding, abetting, sharing intelligence, helping them target ships, determining which are the more lucrative targets,” Mr Lenderking said at a virtual panel discussion hosted by the Middle East Institute think tank on Tuesday.
“We see the very negative role that Iran plays in the region by fanning this conflict. We really hope that those who are messaging the Iranians, and we’ve talked to a number of countries who have relations with Iran – which we of course do not – to talk about the importance of Houthi behaviour undermining the Palestinian effort and generating worldwide animosity toward the Houthis,” Mr Lenderking added.
The special US envoy to Yemen said that diplomatic efforts are under way to try to find a "climbdown" for Yemen's Houthis before his Gulf trip this week that is expected to begin in Oman on Wednesday.
Oman has been a mediator with the Iran-aligned Houthis, who overran the capital Sanaa and Yemen's most populated areas in a civil war that has subsided despite the expiration of a 2022 ceasefire.
Mr Lenderking's comments were made as two ships travelling in Middle East waters were targeted by Houthi rebel ballistic missile fire early on Tuesday.
The first attack happened in the southern part of the Red Sea, west of the Yemeni port of Hodeidah, with the projectile causing “slight damage” to the Barbados-flagged, United Kingdom-owned cargo ship Morning Tide's bridge windows, the British military's United Kingdom Maritime Trade Operations said. A small vessel had been near the ship before the attack, it added.
The Houthis carried out the attack using three anti-ship ballistic missiles, the United States military's Central Command said early on Wednesday.
The Morning Tide’s owner, British company Furadino Shipping, told The Associated Press no one was hurt in the attack and the ship was continuing on to Singapore.
The Houthis say they are acting in solidarity with Palestinians in Gaza and the rebels’ leader on Tuesday vowed to escalate the missile and drone attacks unless Israel halts its operations against the besieged enclave.
Mr Lenderking cited talks held in Oman last week by British Foreign Secretary David Cameron, the Norwegian deputy foreign minister and UN special envoy Hans Grundberg as part of those efforts.
He said the longer the Houthi attacks persisted, the higher the danger of renewed fighting in Yemen and disruptions to food and medicine shipments needed in Yemen and Gaza.
Mr Lenderking said he hopes to hold talks on preserving a roadmap to end the war in Yemen worked out by the Houthis and Saudi Arabia, which intervened on behalf of the internationally recognised government in 2015.