The head of the UN's atomic watchdog Mohamed ElBaradei opened tough talks with senior Iranian officials yesterday to press demands the Islamic republic freeze its controversial nuclear programme.

But ElBaradei's appeals, aimed at heading off a sharp escalation of the crisis, appeared doomed to fall on deaf ears with hardline President Mahmoud Ahmadinejad saying the country's atomic ambitions were not up for negotiation.

The 24-hour visit by the head of

the International Atomic Energy Agency (IAEA) comes two days after Iran announced its scientists had successfully enriched uranium to make nuclear fuel.

The Islamic republic insists its programme is peaceful, but the enrichment process can be extended to make the fissile core of a nuclear warhead. The UN Security Council has set April 28 as a deadline for Tehran to halt enrichment.

"The situation is completely changed. We are a nuclear state," Ahmadinejad said.

"We will not negotiate on our rights with anyone," Ahmadinejad

was quoted as saying by the official news agency IRNA. He added that nobody in the country "has the right to step back one iota from the path we are following."

ElBaradei told reporters that he would be hammering home a UN Security Council demand for Iran to mothball its enrichment programme by April 28.

"We hope to convince Iran to take confidence-building measures including suspension of uranium enrichment activities until outstanding issues are FROM PAGE 12

clarified," ElBaradei said.

"I would like to see Iran has come to terms with the request of the international community," adding that he still remained "hopeful the time is right for political solutions, through negotiations."

ElBaradei opened his discussions with Iran's vice president and Atomic Energy Organisation chief, Gholam Reza Aghazadeh, and was also set to meet Ali Larijani, Iran's top national security official and nuclear negotiator.

The IAEA chief must give a report at the end of April on Iranian compliance with the Security Council deadline.

Representatives of the five permanent members of the Council plus Germany are to meet in Moscow next Tuesday to discuss the crisis, as the long-running stand-off looked set to enter a period of far more robust diplomacy.

US Secretary of State Condoleezza Rice has called for the 15-member Security Council to take "strong steps" and the White House said sanctions were an option.