WASHINGTON — Iran's support for Yemen's Houthi militia is "quite significant and it's lethal" US special envoy on Yemen Tim Lenderking said during a congressional hearing on Wednesday.

The US envoy, who made a back-to-back visit of the region recently, said that the spike in Houthi cross-border attacks on Saudi Arabia is a “very disturbing trend.

Blasting Iran for perpetuating the crisis in Yemen and impeding ceasefire efforts in the war-hit country, Lenderking said there is no real evidence that Tehran wants to support a constructive resolution to the conflict, adding: "We would welcome Iran playing a constructive role if they are willing to do so."

Expressing his concern over the situation in Yemen’s Ma’rib, Lenderking said the Houthi militia offensive on Marib “is the single biggest threat to peace efforts.”

“If we do not stop the fighting in Marib it will trigger a wave of even greater fighting and instability.”

Despite attempts to completely cut off the Iranian arms supply to the Houthi militia, it has been difficult to halt ships bearing weapons from Iran, Lenderking said.

“We need to keep putting continued pressure on the smuggling networks that Iran uses, we need to capture more weapons on their vessels and display them to the international community,” the US envoy to Yemen told lawmakers.

He said that the US needs more international assistance in halting Iran's arms shipment to the Houthi militia.

Asked about what could be done to push back against Iran and the Houthis, the veteran diplomat suggested “naming and shaming” those who continue to provide weapons for continued attacks on civilians. — Agencies