The United States on Friday imposed sanctions on two Iranian individuals and four entities allegedly involved in Tehran's drone program, the Treasury and State departments said.

The latest sanctions come as Washington seeks to heighten pressure on Iran ahead of plans to reopen talks on the country's nuclear program.

Iran's lethal unmanned aerial vehicles or UAVs "have been used in attacks on international shipping and on US forces," the Treasury Department said in a statement.

It also accused Iran's Islamic Revolutionary Guard Corps (IRGC) of supplying drones to Lebanese Shiite group Hezbollah, the Hamas movement and Yemen's Houthi rebel forces.

The Treasury added that the drones have also been seen in Ethiopia, "where the escalating crisis threatens to destabilize the broader region."

"Iran's proliferation of UAVs across the region threatens international peace and stability," Deputy Treasury Secretary Wally Adeyemo said in a statement.

Who are the targets?

All six targets are linked to the IRGC, which the US designated as a terrorist organization in 2019 under former President Donald Trump.

Their assets in the US will be blocked and US citizens will no longer be able to do business with them.

The sanctions singled out Brigadier General Saeed Aghajani, who leads the Revolutionary Guards' UAV command.

The US believes Aghajani was behind a 2019 drone attack on an oil refinery in Saudi Arabia, and another attack in July this year on a commercial ship in the Gulf of Oman.

US Secretary of State Antony Blinken said on Twitter: "We are firmly committed to countering all of Iran's threatening activity and those who support it."

adi/sri (AFP, dpa)