Iranian President Mahmoud Ahmadinejad said on Tuesday more UN sanctions against his country over its nuclear program would not stop Iran but could permanently wreck its ties with the US.

'Sanctions cannot stop the Iranian nation. The Iranian nation is able to withstand the pressure of the US and its allies,' Ahmadinejad told a news conference in New York, where he is attending a United Nations conference.

'While we do not welcome sanctions, we do not fear them either,' he said, speaking through an interpreter.

The US and five other major powers are negotiating a fourth set of UN Security Council sanctions against Iran over its refusal to halt uranium enrichment. They expect the resolution to go through within the next few weeks.

The West accuses Tehran of aiming to develop atomic weapons, but Iran says its nuclear work is for peaceful power generation.

During his 90-minute news conference, Ahmadinejad warned that if new sanctions are passed it 'will mean relations between Iran and the US will never be improved again.'     Diplomatic ties between the two countries were severed in 1980 when Iranian militants were holding more than 50 American diplomats hostage at the US embassy in Tehran.

The Iranian president voiced disappointment about the performance of US President Barack Obama, whom he said was locked in a political stalemate and has failed to keep a promise he made to the UN General Assembly in September to abandon the approach of the previous US administration.

'He promised to reform those policies (of former President George W. Bush) and many of us in the session welcomed those statements,' he said. 'But nothing has happened. No change has come about yet.'    

Russia 'optimistic'

Russian Deputy Foreign Minister Sergei Ryabkov said earlier he was 'optimistic' about the sanctions talks.

'These talks are slowly moving forward,' said Ryabkov, who is Russia's lead negotiator on the Iranian nuclear issue.

'Definitely there is still some space to bridge over, but I wouldn't exaggerate or over-exaggerate the differences.'

UN diplomats from Russia, the US, Britain, France, Germany and China have been meeting nearly every day for weeks to hammer out a draft sanctions resolution.

Russia and China, Western diplomats say, have been pushing the four Western powers to dilute some of the measures in the US-drafted sanctions proposal. Moscow and Beijing have strong commercial ties with Iran.

Ahmadinejad, who like Ryabkov is attending a UN conference on the 1970 nuclear Non-Proliferation Treaty, also said Iran would not withdraw from the treaty like North Korea, another nation whose nuclear program has drawn UN sanctions.

'My presence here means that we want the NPT to be revised, to become a fair system,' he said.

Ahmadinejad repeated the strong condemnation of nuclear weapons he made in a speech on Monday. 'We do not need the atomic bomb and never have we threatened another country,' he said.

'We are able to defend ourselves and our borders.'     Despite his strictures against the United States, Ahmadinejad described as a 'positive step forward' a US decision to disclose for the first time the number of nuclear warheads in the US arsenal.

'Perhaps there should be an independent supervisory body ... that can verify these bombs,' he suggested. – Reuters