TEHRAN, Iran — A prominent Iranian lawmaker confirmed Wednesday that Russia is using an Iranian air base for airstrikes in Syria, as Moscow said another wave of airstrikes launched from the Islamic Republic struck the east of the war-ravaged country.

The comments by Alaeddin Boroujerdi, the head of the Iranian parliament’s national security and foreign policy committee, are the first official acknowledgment that Russian planes are flying out of Iran’s Shahid Nojeh Air Base.

Meanwhile, Russia’s foreign minister rejected allegations that its use of Iranian military bases for airstrikes in Syria violates United Nations sanctions on Iran.

Russia on Tuesday first announced that it had launched the strikes from near the Iranian city of Hamedan and struck targets in three provinces in northern and eastern Syria. The Defense Ministry on Wednesday announced a new wave of airstrikes out of Iran, saying its jets took off earlier in the day from a base southwest of the Iranian capital, Tehran, to strike targets in the east of Syria.

It is virtually unheard in recent history for Iran to allow a foreign power to use one of its bases to stage attacks. Russia has also never used the territory of another country in the Middle East for its operations inside Syria, where it has been carrying out an aerial campaign in support of President Bashar Assad’s government for nearly a year. Iran is also a major supporter of Assad.

Boroujerdi said that Russian’s fighters land at Shahid Nojeh Air Base only to refuel under the permission of the country’s Supreme National Security Council.

“Generally, there is no stationing of Russian forces in the territory of the Islamic Republic of Iran,” Boroujerdi said.

Russian Foreign Minister Sergey Lavrov on Wednesday denied allegations by U.S. State Department spokesman Mark Toner, who the day before said Russia’s operation out of Iran could violate the U.N. resolution that prohibits the supply, sale and transfer of combat aircraft to Iran unless approved by the Security Council.

“In the case we’re discussing there has been no supply, sale or transfer of fighter jets to Iran,” Lavrov told a news conference. “The Russian Air Force uses these fighter jets with Iran’s approval in order to take part in the counter-terrorism operation” in Syria.

The minister also called on the U.S. not to “nitpick about what is happening in terms of the remaining restrictions on trade and ties with Iran.”