Russia has dismissed a suggestion from Washington that Moscow is violating a United Nations Security Council resolution by using an Iranian air base for its bombing raids on Syria.

Foreign Minister Sergei Lavrov on Wednesday denied that Moscow could be in breach of a ban on supply or transfer of warplanes to Iran without prior approval of the UNSC.

There are no grounds to suspect Russia of breaching the resolution, Lavrov said at a news conference in Moscow.

Russia on Tuesday began flying warplanes from an Iranian airbase in a major switch in its bombing campaign in Syria that the United States condemned as unfortunate.

Washington responded to Lavrovs latest statements on Wednesday, saying it is evaluating Russias actions.

Russian forces took off from the Iranian base to carry out a fresh round of strikes on Wednesday morning.

Russia has previously flown raids only out of its bases in Syria and Russia.