Iran's hardline President Mahmoud Ahmadinejad has promised a global response if his country is attacked, in an interview with Qatari daily Al-Sharq published on Saturday.
"Our options will have no limits... They will touch the entire planet," he said in reply to a question about Tehran's reaction in the event of such an attack.
Iran's arch-foes the United States and Israel have never ruled out military strikes against Tehran to halt its nuclear programme which they and other Western powers suspect is aimed at making weapons.
Tehran denies the charge, saying its atomic programme has purely peaceful goals. "I believe that some think about attacking Iran, especially those within the Zionist entity (Israel).
But they know that Iran is an indestructible bulwark and I do not think their American masters will let them do it," Ahmadinejad said. "They also know that the Iranian response will be hard and painful," he added. The UN Security Council in June slapped its fourth set of sanctions on Iran over its refusal to halt its uranium enrichment work.