President Mahmoud Ahmadinejad said on Thursday Iran had overcome difficulties en route to a nuclear energy industry and no one could stop it.
Diplomats said Iran had installed close to 3,000 centrifuge machines, enough to start refining usable amounts of nuclear fuel, but would need to run them in unison at high speeds for long periods to attain that threshold.
The UN nuclear watchdog director told the Financial Times daily on Tuesday that Iran was feeding uranium into centrifuges for enrichment at only 10% of their capacity and remained "far from having a nuclear weapon," assuming Tehran wanted one.
"I announce to the whole world that the Iranian nation has passed the difficult points (on its nuclear path)," Ahmadinejad said in remarks carried by Iran's official news agency IRNA.
"And no power can stop this nation from making more and more (atomic) achievements," he said.
Previous remarks about an enrichment breakthrough by Ahmadinejad, including a proclamation in April of industrial capacity, have lacked evidence and elicited skepticism abroad.
Diplomats close to the watchdog International Atomic Energy Agency originally expected Iran to have 3,000 centrifuges running by May or June. But in July the IAEA reported a slowdown in the program which continued at least into mid-September.