MOSCOW — Any airstrike against Iran by the United States or Israel would be “unacceptable,” the chief of the Russian General Staff Nikolai Makarov said on Monday.

“This is a last resort that exists in the plans of both the United States and Israel,” Nikolai Makarov said.

Western powers suspect that Iran’s nuclear program is aimed at making weapons, while Tehran claims it is pursuing nuclear technology for its civilian energy needs.

Makarov said that the Iranian leadership should also take into account that “the whole world is concerned about the [nuclear] problem.”

“We should hear Iran and Iran should hear us and the global community, and undertake measures,” Makarov added.

He also said that other states are likely to follow suit if Iran develops nuclear weapons.

“If Iran gets nuclear weapons, it might become an impetus for other states, and lead to further expansion of the nuclear club,” he said, adding the Russian military department was against such a scenario.

He added that Russia’s decision on whether to deliver S-300 surface-to-air missile systems to Iran should be made by the country’s leaders.

“This decision should be made at state level. We, the military, will follow the leadership’s commands,” Makarov said.

Russia signed a contract with Iran on the supply of at least five S-300 air defense systems to Tehran in December 2005. However, Moscow has not so far honored the contract, which many experts say is due to pressure from Washington and Tel Aviv.

Both the United States and Israel have not ruled out military action if diplomacy fails to resolve the dispute over Iran’s nuclear program and have expressed concern over S-300 deliveries, which would significantly strengthen Iran’s air defenses.