UN Security Council member Turkey offered on Tuesday to help break a deadlock over an atomic fuel deal for Tehran and insisted that diplomacy is the best way to resolve Iran's nuclear crisis.

"The solution for Iran's nuclear programme is through negotiations and the diplomatic process," Turkish Foreign Minister Ahmet Davutoglu told a news conference on a visit to Tehran.

Davutoglu said that Turkey, which has resisted a US push for a fourth round of sanctions against Iran, "is ready to act as an intermediary in the issue of uranium exchange as a third country and hopes to have a fruitful role in this."

"We will continue to try our best to see what we can do for this nuclear fuel swap," he added.

He was referring to a plan drafted by the UN nuclear watchdog last October that would have seen the major powers provide fuel for a Tehran research reactor in return for Iran shipping abroad most of its stocks of low-enriched uranium.

Iranian Foreign Minister Manouchehr Mottaki, who addressed reporters alongside Davutoglu, did not explicitly respond to the latest Turkish offer but said there were regular consultations between the two governments on the nuclear issue.

"Turkey will do its part if Iranians deem fit," Davutoglu said in reply.

Talks between Iran and the major powers on the UN nuclear fuel plan have been deadlocked over Iran's insistence that it only hand over its enriched uranium stocks as the fuel is supplied, and that the exchange take place on its own soil.

For Western governments, the prior removal abroad of a large part of Iran's enriched uranium stocks is the centrepiece of the plan. They fear that Iran might otherwise covertly enrich the uranium to the far higher level required for a bomb, an ambition Tehran strongly denies.

Turkey has been hoping that its good relations with both Iran and the West may open the way to a compromise in which the uranium would be stockpiled on its soil until the nuclear fuel has been supplied to Iran.

Iran's decision to start enriching its own fuel for the Tehran reactor in February without waiting for a supply deal with the major powers infuriated Western governments who have since been pushing for a new package of sanctions at the UN Security Council.

But they have met resistance from veto-wielding permanent member China, as well as Turkey, Brazil and Lebanon.

And on Friday, President Mahmoud Ahmadinejad is to visit Uganda, also a council member, for talks with his counterpart Yoweri Museveni that officials said would touch on the nuclear issue.

"Obviously as a member of the Security Council we are going to discuss the issue of nuclear energy," Ugandan foreign ministry permanent secretary James Mugume told AFP.

Mottaki said at the weekend that Iran would make contact with all 15 council members, indirectly in the case of the United States, on the fuel swap plan.

On Monday, he said he believed a deal was still possible.

"If the other side has serious political will for the fuel exchange formula, this can be a multilateral trust-building opportunity, especially for the Islamic republic to trust the other side," he said.

On Sunday, Washington expressed interest in reviving the fuel plan but said the original UN draft needed to be "updated."

"At the heart of this was the proposal that Iran would ship out significant amounts of enriched fuel and there would be an exchange for a corresponding amount of fuel suitable for" the Tehran reactor, State Department spokesman Philip Crowley said.

"Iran has never agreed to that element of the offer."

Crowley said any new plan would have to be amended to take account of the fact that Iran has had seven months since the original offer in which to enrich further stocks of uranium.

Under the October draft, Iran would have been expected to ship out 70 percent of its then stocks of low enriched uranium in return for the supply of fuel by France and Russia.