At a military hangar in Washington, Brian Hook, the US special representative for Iran, showed reporters a collection of guns, rockets, drones and other gear. Some of these had been intercepted in the Strait of Hormuz en route to Shia fighters in the region while others had been seized by the Saudis in Yemen, the Pentagon said.

The presentation -- very similar to a December 2017 event led by the US ambassador to the United Nations Nikki Haley -- is part of an ongoing push by President Donald Trump's administration to increase pressure on Tehran and shame Western allies into doing more to tackle Iran's regional influence.

The centerpiece of the display was what Hook said is a Sayyad-2 surface-to-air missile system that the Saudis had intercepted in Yemen this year.

Farsi writing along the white rocket's side helped prove it was Iranian made, he said.

"The conspicuous Farsi markings is Iran's way of saying they don't mind being caught violating UN resolutions," Hook told reporters, adding the missile was destined to Huthi rebels who are fighting the Saudi-led coalition in Yemen.

"The Iranians wanted to deliver this to the Huthis, who would have used it to target coalition aircraft up to 46 miles away."

- US lawmakers frustrated with Saudis -

The presentation came a day after US senators voted to advance a measure that could end US military support for the Saudi-led intervention in Yemen.

Lawmakers have grown increasingly frustrated with Saudi Arabia after the murder of Saudi dissident journalist Jamal Khashoggi, whose death has been tied to Riyadh.

Hook also displayed anti-tank guided missiles that the US says Iran had provided to the Taliban in Afghanistan. They were recovered in Kandahar by the Afghan army, he said.

"Iran has been providing material support to the Taliban since at least 2007," Hook said.

Washington this year pulled out of a pact with Iran aimed at constraining its push for nuclear weapons.

Hook said that since leaving the deal, US officials have found "freedom and leverage" to tackle Iran's regional influence, and he chided other nations for not getting on board.

"The current international environment has created unacceptably low expectations for the regime in Tehran," he said.

If "the demands of ... the Iranian regime seem too many, it is because Iran's malign activities are too numerous."