HOUSTON, Texas

Iran is supplying Russia with hundreds of combat drones to help with its efforts in the war against Ukraine, according to Western intelligence officials.

Transport planes departed Iran on Aug. 19 carrying the initial load of unmanned aerial vehicles (UAVs) to help Russian forces, The Washington Post reported late Monday.

The drones are capable of carrying ammunition for attacks on radar stations, artillery and other military targets from information gathered by US and other spy agencies.

The supplying of these weapons shows a clear alliance between Russia and Iran, with Moscow and Tehran brokering the deal in a joint effort to try to gain an advantage in the Ukraine war.

However, as much as the arrival of these weapons could fortify Russia's military offensive, reports from US security officials have surfaced that the new drones have been plagued with technical difficulties, with the Iranian weapons experiencing numerous failures during initial testing.

"There are a few bugs in the system," according to an allied security official interviewed by the Post. "The Russians are not satisfied."

The Russian military has access to between 1,500 and 2,000 surveillance UAVs, but the Iranian shipment provides Russia with weapons of which they are in short supply: attack drones capable of delivering precision strikes against targets deep inside enemy territory.

On the other side of the battlefield, Ukraine has used Turkish-made combat UAVs that have been effective in destroying Russian armor, trucks and artillery.

In addition, the US has also aided Ukraine with the High Mobility Artillery Rocket System (HIMARS), which can launch multiple rockets with precision at Russian ammunition depots and logistics supplies from nearly 50 miles away.

"The Russians have no way to limit the damage HIMARS are inflicting on them now," said Dmitri Alperovitch with the Washington, D.C.-based Silverado Policy Accelerator think tank in an interview. "They hope attack drones can help."

The Biden administration warned Tehran not to ship the drones to Russia, but intelligence officials said those warnings were ignored.

Even though the weapons are considered to be among Iran's most sophisticated UAVs, their apparent poor quality is rendering many of the combat drones ineffective at this point.