Iranian President Mahmoud Ahmadinejad said today it was "too late" to stop Iran's nuclear programme.
President Ahmadinejad told at a news conference that despite international pressure, Iran has only become stronger.
He also urged the West and the United States to abandon their "arrogant policies" of setting conditions.
The Iranian leader appeared to dismiss ambitions of using the controversial nuclear programme for weapons making. "What is atomic bomb good for? Thoughts can't be changed by nuclear bomb. Today is the day of thought and logic," he said.
Washington and some of its allies fear Iran is trying to develop atomic weapons in violation of its commitments under the Nuclear Nonproliferation Treaty. Iran denies the accusations and says the treaty gives it the right to pursue uranium enrichment for peaceful purposes.
The UN Security Council first imposed sanctions on Iran in December and modestly increased them in March over Iran's refusal to suspend enrichment. The council is now preparing to debate on a third round of punitive measures.