Iran would respond militarily if the United States attacks the country to disrupt its nuclear program, Iran's official IRNA news agency quoted a senior official as saying on Wednesday.

"Naturally a military action will have a military response," chief nuclear negotiator Ali Larijani said when asked if Iran would strike back if attacked by the United States. " ... our response will be appropriate."

The United States and other world powers suspect Iran wants to build atom bombs, a charge Tehran denies.

Washington insists it wants a diplomatic solution to the standoff, but has not ruled out military action if that fails. Iran's Supreme Leader Ayatollah Ali Khamenei has threatened U.S. regional interests if attacked.