White House spokesman John Kirby said on Tuesday that Iran may be considering to provide Russia with ballistic missiles for use in Ukraine.

He further stated that the United States would monitor the situation between Iran and Russia and take appropriate action as needed.

Iran has already provided Russia with armed drones, guided aerial bombs and artillery shells, the Wall Street Journal cited US officials as saying on Tuesday.

The WSJ report said Washington’s concern about the expanding military cooperation between Iran and Russia grew when Iran showed its Ababil and Fateh-110 missiles to Russian Defense Minister Sergei Shoigu when he visited Tehran in September.

“We are therefore concerned that Iran is considering providing Russia with ballistic missiles for use in Ukraine,” a spokesman for the National Security Council said.

In October, when UN sanctions on Iran's missile program expired, Russia announced plans to deepen military ties with Tehran. "Now, after the expiration of some restrictive provisions of resolution 2231, there are fewer such restrictive regimes. Naturally, we will be using this, and it should not raise any questions for anyone,” Russia's Deputy Foreign Minister Sergei Ryabkov said.

Tehran has denied allegations of sending armed drones to Russia during Moscow's invasion of Ukraine. The Iranian government stated that any such shipments, if they did occured, took place before the war.

Nevertheless, Russia's utilization of Iranian-made drones for attacks on Ukrainian infrastructure and civilian targets has drawn international criticism. Western powers have raised concerns over Iran's involvement in arming Russia, along with the possibility of supplying additional weaponry and ammunition.