The US announced sanctions against an Iranian company as well as companies in China, Turkey and the United Arab Emirates for allegedly supporting Iran’s “one-way attack” drone program by supplying critical components.

As of July, it is believed that Iran has provided Russia with more than 400 Shahed 131, 136 and Mohajer drones for use in its war in Ukraine.

“Iranian-made UAVs continue to be a key tool for Russia in its attacks in Ukraine, including those that terrorize Ukrainian citizens and attack its critical infrastructure,” said Under Secretary of the Treasury for Terrorism Brian Nelson in a statement.

The sanctions are against the Iranian firm Pishgam Electronic Safeh Company and its CEO Hamid Reza Janghorbani for procuring “hundreds of thousands of dollars” worth of servomotors that can be used in Iran’s attack drones.

“One of the servomotors procured by the network designated today was recovered in the remnants of a Russia-operated Shahed-136 that was recently shot down in Ukraine,” said State Department spokesperson Matthew Miller in a statement.

The sanctions also target the Hong Kong-based company Hongkong Himark Electron Model Limited and “PRC-based Hongkong Himark official” Fan Yang for selling more than $1 million worth of servomotors to Iran, as well as two Turkish companies that “facilitated financial transactions totaling hundreds of thousands of dollars” to procure the servomotors from Hongkong Himark and a UAE-based firm that facilitated servomotor shipment.

More background: Russia is primarily using the drones to attack critical Ukrainian infrastructure and stretch Ukraine’s air defenses, according to a senior Defense Intelligence Agency official. The US obtained and analyzed several of drones downed in Ukraine, and officials say there is “undeniable evidence” that they are Iranian, despite repeated denials from Tehran that it is providing the equipment to Russia for use in Ukraine.