THE US is ready to protest directly to UN nuclear chief Mohamed ElBaradei over his comments that Iran should be allowed to keep some uranium enrichment, diplomats said today.

"They have decided to do so. It will maybe be before the report comes out" tomorrow, a diplomat said, referring to an ElBaradei report on Iran's nuclear activities.

A second diplomat said US ambassador Gregory Schulte is expected, possibly along with ambassadors from US allies, "to speak to Mr ElBaradei and complain".

Mr Schulte's spokesman refused to comment.

The United States leads Western nations in insisting that Iran freeze all enrichment work in order to start talks on trade, security and technology benefits for Tehran in return for guarantees it will not seek nuclear weapons.

Iran is defying demands and sanctions from the UN security council for it to suspend uranium enrichment, which the West fears could be used to develop nuclear weapons.

Iran says it needs to enrich to produce fuel for nuclear reactors in order to eventually produce electricity.

Some diplomats have been talking about a possible compromise in which Iran would be allowed to continue research into enrichment, at a time of diplomatic initiatives by both the United States and the European Union with Iran.

Mr ElBaradei, head of the UN watchdog International Atomic Energy Agency (IAEA), had told The New York Times earlier this month that Iran has progressed in its enrichment work.

"From a proliferation perspective, the fact of the matter is that one of the purposes of suspension (of uranium enrichment) - keeping them from getting the knowledge - has been overtaken by events," he said.