The White House said on Monday that it would announce in the coming days new sanctions against "those involved in supplying Russia with weapons from Iran," explaining that Moscow is seeking advanced drones from Tehran.
John Kirby, coordinator of strategic communications at the US National Security Council, said that since August, Iran has provided Russia with more than 400 drones and artillery shells for use in Ukraine.
Kirby also said that Washington sees signs that Russia and Iran are expanding an unprecedented defense partnership that will help Moscow prolong its war on Ukraine, explaining that Moscow is seeking advanced types of Iranian drones.
In return, Tehran is seeking billions of dollars worth of attack helicopters, radars and training planes from Moscow, the strategic communications coordinator said.
The U.S. official described Iran as one of Russia's biggest backers in its war on Ukraine, but said Washington saw no signs of Iran providing ballistic missiles to Russia.
Previous sanctions
In January, the United States imposed sanctions on suppliers of Iranian drones, which Washington said Moscow used to target civilian infrastructure in Ukraine.
The US sanctions affected six executives and board members of the Jerusalem Aerospace Industries Company, also known as the Light Aircraft Design and Manufacturing Industries.
Earlier, Washington imposed sanctions on companies and people it accused of producing or transporting Iranian drones used by Russia in the Ukraine war.
Iran acknowledged sending drones to Russia, but said it sent them before the war on Ukraine began in February 2022.
Moscow has denied its forces have used Iranian drones in Ukraine.