Russia has expressed surprise at Iran's decision to file a suit with an international court over Moscow's cancellation of a missile contract.

A spokesman for Russia's Foreign Ministry said Thursday Russia acted in accordance with United Nations Security Council resolutions. The spokesman said Russia had no choice but to cancel the long-agreed delivery of ground-to-air missiles because of the U.N. sanctions.

He added that the two countries should find “mutually acceptable” ways to resolve disagreements.

Russian media report Iran's ambassador to Moscow, Mahmoud Reza Sajjadi, announced on Wednesday that Tehran had lodged a complaint against Russia with an international court of arbitration because of its refusal to supply Iran with S-300 air defense missile systems. He did not specify which court.

Russia had wanted to sell Iran its S-300 surface-to-air missile system but scrapped the plan last year after the U.N. toughened its existing sanctions against Iran.

The U.N. Security Council has slapped Iran with four rounds of sanctions due to its refusal to cooperate on its nuclear program.

Many Western nations, including the United States, accuse Iran of pursuing nuclear weapons. Tehran insists its nuclear program is for peaceful purposes.