TEHRAN, Oct 18 (Reuters) - Iran has promised to provide Russia with surface to surface missiles, in addition to more drones, two senior Iranian officials and two Iranian diplomats told Reuters, 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.

A Western official briefed on the matter confirmed it, saying there was an agreement in place between Iran and Russia to provide surface-to-surface short range ballistic missiles, including the Zolfaghar.

One of the drones Iran agreed to supply is the Shahed-136, a delta-winged weapon used as a "kamikaze" air-to-surface attack aircraft. It carries a small warhead that explodes on impact.

Fateh-110 and Zolfaghar are Iranian short-range surface to surface ballistic missiles capable of striking targets at distances of between 300 km and 700 km (186 and 435 miles).

The Iranian diplomat rejected assertions by Western officials that such transfers breach a 2015 U.N. Security Council resolution.

"Where they are being used is not the seller's issue. We do not take sides in the Ukraine crisis like the West. We want an end to the crisis through diplomatic means," the diplomat said.

Ukraine has reported a spate of Russian attacks using Iranian-made Shahed-136 drones in recent weeks. Iran's foreign ministry on Tuesday dismissed as baseless reports of Iran supplying drones and other weapons to Russia for use in Ukraine, while the Kremlin on Tuesday denied its forces had used Iranian drones to attack Ukraine.

Asked if Russia had used Iranian drones in its campaign in Ukraine, Kremlin spokesman Dmitry Peskov said the Kremlin did not have any information about their use.

"Russian equipment with Russian nomenclature is used," he said. "All further questions should be directed to the Defence Ministry."

The ministry did not immediately reply to a request for comment.

The appearance of Iranian missiles in addition to drones in Moscow's arsenal in the war with Ukraine would raise tensions between Iran and the United States and other Western powers.