A visit by the head of the United Nations nuclear watchdog agency has done nothing to persuade Iran to respond to international demands and halt its uranium enrichment program.

Mohammed ElBaradei said he cannot confirm Iran's claim that it has enriched uranium to the point it can be used to generate power but short what is needed for nuclear weapons. Nevertheless, he asked Tehran to stop whatever it is doing.

Tuesday's enrichment claim sparked international condemnation and a warning from the United States that UN sanctions are coming soon.

Mohammed ElBaradei (CP file photo)

Iranian President Mahmoud Ahmadinejad responded by saying those who are angry with Iran should "be angry and die of this anger."

In Iran, newspapers have been running headlines praising their president's announcement that Iran has joined the world's "nuclear club." One conservative paper called for a week of celebration and the creation of an annual public holiday.

Some hardliners set up nuclear celebration tents at roadsides around Tehran and handed out sticky pastries to passers-by.

Mohsen, a 24-year-old university student, called the announcement great news for Iran's future. "This is good for all countries. After 100 years, I don't know what Iran's capacity is for oil and gas. After some time, it will finish," he said.

Ahmadinejad said this week his country has enriched uranium to the level needed to power nuclear reactors. That's not enough to make nuclear weapons and Iran says it only plans to generate electricity.

But ElBaradei said his agency is still investigating Iran's program and, after holding talks with Iranian officials on Thursday, he told reporters his agency is still investigating whether Iran has enriched uranium to the level it says it has.

He called on Iran to suspend its sensitive nuclear activities in order to build international confidence.

"We have not seen diversion of nuclear material for weapons purposes, but the picture is still hazy and not very clear," he said.

The UN Security Council has also called on Iran to halt all enrichment work by the end of this month. But Ali Larijani, Iran's top nuclear negotiator, said this demand is "not very important."

Larijani also brushed aside proposals to move Iran's uranium enrichment program to another country. "The agency's inspectors are here in Iran and the cameras are supervising our nuclear activities, so the idea of uranium enrichment in another country is not a good idea and cannot solve the problem."

Most Iranians say they believe their country won't use its newfound technology to make nuclear weapons.

"Like everyone else in the world, we're worried about using nuclear energy in the wrong way. We hope the Iranian government keeps its promises so it doesn't threaten world peace," said 37-year-old Peiman.

Some Iranians are also concerned that Tuesday's announcement will increase international pressure on Iran . They worry that the United States will now push harder for sanctions, or possibly launch a military strike.

President George W. Bush has said he wants to use diplomacy to solve the nuclear standoff but he won't rule out using military force.

ElBaradei is expected to report on Iran's nuclear activities to the UN Security Council and the International Atomic Energy Agency by the end of the month.