Iran has promised to provide Russia with surface-to-surface missiles, in addition to more drones, two senior Iranian officials and two Iranian diplomats have said, a move that is likely to infuriate the United States and other Western powers.

A deal was agreed on Oct. 6 when Iran's First Vice President Mohammad Mokhber, two senior officials from Iran's powerful Revolutionary Guards and an official from the Supreme National Security Council visited Moscow for talks with Russia about the delivery of the weapons.

"The Russians had asked for more drones and those Iranian ballistic missiles with improved accuracy, particularly the Fateh and Zolfaghar missiles family," said one of the Iranian diplomats, who was briefed about the trip.