TEHRAN (Reuters) - Iran will stand firm against U.S. "bullying" over its nuclear programme but will never use atomic technology to make bombs, the Islamic Republic's Supreme Leader Ayatollah Ali Khamenei said on Friday.
"This nation is not a nation that would succumb to the impositions and bullying of the U.S. or any other," Khamenei told worshippers in a Friday prayers sermon at Tehran University.

"The U.S. politicians who claim Iran seeks nuclear weapons know very well that they are lying ... their purpose is to earn dominance. Human rights is of no value to them," he said to shouts of "God is Greatest" and "Death to America" from the thousands of people packed in and around the university.

Washington says Iran's 18-year cover-up of nuclear activities suggest it is trying to build nuclear weapons under the pretext of a peaceful atomic energy programme.

Iran says it needs nuclear energy to meet booming demand and that its top religious leaders have prohibited it from ever using atomic weapons.

"In the nuclear energy field, our purpose has nothing to do with nuclear weapons, nor would this technology ever be diverted into (making) weapons," said Khamenei, who has the last word on all state matters.

"However the Iranian nation will not give up on this technology," he added.

Negotiations between Iran and the European Union over its nuclear programme broke down in August. In September the board of governors of the International Atomic Energy Agency (IAEA) passed a tough resolution which brought Tehran to the brink of referral to the U.N. Security Council for possible sanctions.

But diplomats have told Reuters that Iran's cooperation with the IAEA has improved since then and that the EU will probably not try to force Iran's case to the Security Council at the next IAEA board meeting in November.

A senior U.S. official called on Iran to return to the negotiations.

"Our belief is that Iran should come back to negotiations," said Undersecretary of State Nicholas Burns during a visit to India. "They unilaterally abrogated the negotiations with the European three in August."

"Iran is a country that most of the world believes is trying to create a nuclear weapons future. It's also a country that is the leading supporter and funder of the major terrorist groups in the Middle East," he said.

He added: "If Iran does not come back to negotiations, then there is every reason to believe that there will be a vote at the IAEA board of governors on Nov 24."

Iran feels efforts to stop it advancing its nuclear programme are discriminatory.

"The Iranian nation does not accept that achieving nuclear science could be permitted for one country and prohibited for another on baseless grounds," Khamenei said.