Reuters reports than Iran President Mahmoud Ahmadinejad said on June 26 that Iran’s “enemies” would never succeed in stopping its nuclear activities.

“On the nuclear issue … the enemies were not able to stop our nation and will never succeed in stopping our program,” Ahmadinejad said in a speech in late June.

Tehran said on Tuesday that new punitive measures imposed on it this week by the 27-nation European Union over its nuclear plans could damage diplomatic efforts to resolve the dispute.

Tehran has so far refused to suspend its sensitive nuclear work and has warned major powers pressuring Iran could backfire.

The stand-off has sparked fears of a military confrontation that would disrupt oil supplies from the Gulf. Last week a report said Israel had practiced for a possible strike against Iran’s nuclear facilities.

Washington says it is focusing on diplomatic pressure to thwart Iranian nuclear work but has not ruled out military action if that were to fail.