Iran said Tuesday its nuclear and foreign policies will not change after President Mahmoud Ahmadinejad abruptly fired Foreign Minister Manouchehr Mottaki and replaced him with the atomic chief.

No official reasons were given for the surprise move, but several Iranian newspapers on Tuesday linked it to disagreements between Ahmadinejad and Mottaki over foreign policy.

"Iran's major international policies are defined in higher levels and the foreign ministry executes these policies. We will not see any changes in our basic policies," foreign ministry spokesman Ramin Mehmanparast said at his weekly briefing.

"I don't think there will be any changes in the nuclear policy and the talks" with world powers over Iran's nuclear programme, he said.

Ahmadinejad on Monday named Ali Akbar Salehi, a vice-president and head of Iran's atomic energy organisation, as interim foreign minister.

The president came under fire from some MPs and Iran's leading hardline daily Kayhan Tuesday for announcing the dismissal while Mottaki was in Senegal on an official visit.

"Such moves cheapen the status of the foreign ministry. It means the president does not respect the person who is delivering his own message to another country," senior conservative MP Ahmad Tavakoli told Mehr news agency.

Kayhan said Ahmadinejad should have waited for the return of the chief diplomat before announcing the sacking. Mottaki is due back in Tehran on Tuesday night.

His sacking came just days after Iran held crunch talks in Geneva on December 6 and 7 with world powers over its controversial nuclear dossier.

Further talks are scheduled for next month in Iran's neighbour Turkey despite clear differences at the end of Geneva meeting between Iran and the group of P5+1 -- Britain, China, France, Germany, Russia and the United States.

EU foreign policy chief Catherine Ashton, who represented the major powers, said it had been agreed at the Geneva talks to hold further talks to "discuss practical ideas and ways of cooperating towards the resolution of our core concerns about the nuclear issue."

However, Iran's chief nuclear negotiator Saeed Jalili said both sides agreed only to further "talks based on cooperation."

Mehmanparast repeated on Tuesday that "it has been agreed that talks be pursued for cooperation in common points."

"If the atmosphere of talks is free of pressure and irrational behaviour, talks have their own framework and will follow their own course," he added.

Salehi, 61, who was appointed atomic energy chief on July 17, 2009, has been a driving force behind Iran's atomic programme, and during his tenure the country's first nuclear power plant has come on line.

Several conservative papers linked the sacking to a dispute between Mottaki and Ahmadinejad over "parallel diplomacy," which flared up in summer after the president named his close aides as special envoys in the region.

Ahmadinejad backed down only after Iran's supreme leader Ayatollah Ali Khamenei intervened.

Some media said Ahmadinejad was trying to tighten his grip on diplomacy in the face of a reticent foreign ministry.

"The government has been known for its active and aggressive diplomacy but it was mainly in the president's moves and initiatives and the foreign ministry did not have an acceptable record in this regard," pro-Ahmadinejad hardline website Rajanews said.

"Sometimes diplomats in unofficial meetings even denied the government's official policies," it added.

Khabar newspaper, which is close to Ahmadinejad's rival, parliament speaker Ali Larijani, predicted that Salehi will be "one of the managers to form a new circle in the government although he is not ideologically linked with the president."

"Ahmadinejad knows well that Salehi appeals to the West for his moderate views," it added.

Salehi is a PhD graduate of the prestigious MIT in the United States and served as Tehran's representative in the Vienna-based International Atomic Energy Agency during the presidency of the reformist Mohammad Khatami.

Mottaki, 57, a career diplomat, was appointed foreign minister in August 2005.