Iran supplied Yemen's Houthi rebels with weapons technology that helped the militants to attack Saudi Arabia, according to Rostam Ghasemi, a senior official in the Islamic Revolutionary Guard Corps and Iran's former economy minister.
Mr Ghasemi's admission is the first time Iran has confirmed it is helping the Houthis militarily.
Iran is providing "limited military advice", the Quds Force representative told Russia Today on Wednesday.
"We helped them with weapons manufacturing technology but the actual production of weapons is done in Yemen. They produce the weapons themselves. These drones and missiles are made in Yemen," he said. "There is no need to send weapons."
A representative of Iran's Foreign Ministry rejected Mr Ghasemi's comments.
"Iran's support for Yemen is political support," the ministry said.
Mr Ghasemi said a handful of Iranian military advisers are in Yemen.
"We have provided weapons in a very limited way. We have provided more consultations compared to supplying weapons to Yemen," he said.
The Houthis escalated attacks against Saudi Arabia in recent weeks, increasingly taking aim at civilian infrastructure.
Houthi military spokesman Yahya Saree recently claimed a number of attacks against Saudi Arabia's state oil centres, but Riyadh has not confirmed the incidents.
The US voiced concern on Wednesday about Iran's support for the Houthi movement.
Tehran's role is "quite significant and it's lethal", Tim Lenderking, the US special envoy on Yemen, said as he called a battle for the country's gas-rich Marib region the single biggest threat to peace efforts.
Mr Lenderking said Iran backs the Houthis in several ways including through training, providing lethal support and helping them to "fine tune" their drone and missile programmes.
"Unfortunately, all of this is working to very strong effects as we see more and more attacks on ... Saudi Arabia and potentially other countries – more accuracy and more lethality. So this is a great concern to us," Mr Lenderking told the US House of Representatives' Foreign Affairs Committee.
"We would welcome Iran playing a constructive role, if they are willing to do so. We have not seen any indication of that," he said.
A Saudi-led military coalition intervened in Yemen in 2015 after the Iran-aligned Houthi group ousted the country's government from the capital, Sanaa.
A spokesman for Iran's mission to the UN in New York dismissed Mr Lenderking's remarks.
The US sanctioned Mr Ghasemi in 2019 for "acting for or on behalf of the former Quds Force Commander Qassem Suleimani".
After Suleimani was killed in a US air strike last year, Mr Ghasemi assumed a portion of Suleimani's work in arranging shipments of oil and petroleum products for the financial benefit of the IRGC, including to Syria, the US said.
