Iran's support for Yemen's Houthi militias is "quite significant and it's lethal" and there is no real evidence that Tehran wants to support a constructive resolution to the conflict, US special envoy on Yemen Tim Lenderking told US lawmakers on Wednesday.
"We would welcome Iran playing a constructive role, if they are willing to do so," Lenderking said. "We have not seen any indication of that."
The Houthi offensive in the gas-rich Marib region is "the single biggest threat to peace efforts", Lenderking added, warning that if the fighting is not stopped "it will trigger a wave of even greater fighting and instability."
He acknowledged that it has been difficult to halt ships bearing weapons from Iran to the Houthis.
The US needs more international assistance in halting Iran arms shipment to the militias, Lenderking urged.
Moreover, the envoy said the increase in Houthi cross-border attacks on Saudi Arabia is "very disturbing trend".