Russian air defense system missile system Antey 2500, or S-300 VM, is on display at the opening of the MAKS Air Show in Zhukovsky outside Moscow.

Russia and Iran have signed a contract for Moscow to supply Tehran with S-300 surface-to-air missile systems, Sergei Chemezov, the chief executive of Russian state-owned defence conglomerate Rostec, was quoted by the RIA news agency as saying on Monday.

“S-300, the air defence system, the contract has already been signed,” Chemezov was quoted as saying at the Dubai Airshow.

A nuclear deal signed between Iran and world powers earlier this deal has put Sunni-ruled Gulf monarchies on edge: They fear Tehran’s rapprochement with the West will allow it to pursue an expansionist agenda in the region.

Chemezov said Gulf countries had no reason to feel threatened by the deal.

“This is defence equipment. And we are ready to offer this defence equipment to any country,” Chemezov later told Reuters in Dubai, speaking through interpreters.

“So if the Gulf countries are not going to attack Iran … why should they be threatened? Because this is defence equipment.”

He added: “Five years ago … even now, up to now … And we said that the S-300 is not capable to attack … to reach the neighboring countries.”