Iran's President Mahmoud Ahmadinejad faces pressure at home against a nuclear fuel exchange deal with world powers, according to a US diplomatic cable made available by WikiLeaks on Tuesday.

Turkey's Foreign Minister Ahmet Davutoglu, in a meeting with a senior US envoy, said Ahmadinejad was facing "serious domestic problems inside Iran," in the November 2009 cable on the whistle-blowing website.

The cable quoted him as saying Ankara "actually see Ahmadinejad as 'more flexible' than others who are inside the Iranian government."

The president, regarded as a hardliner abroad, was up against "huge pressure" because a nuclear exchange deal would be "interpreted by some circles in Iran as a virtual defeat."

Ahmadinejad had told Ankara more than a year ago that "the Iranians agree to the proposal but need to manage the public perception," according to the classified cable from the US embassy in Turkey.

World powers have since 2009 offered Iran a deal to transfer its low-enriched uranium (LEU) to Russia in exchange for high-grade uranium for a Tehran nuclear research reactor.

Davutoglu also gave an assessment that Tehran had "more trust" in the United States, its arch-foe, than Russia, which helped build Iran's sole nuclear power plant, to deliver the nuclear fuel, the cable revealed.

Iran is to meet with Britain, China, France, Russia, the United States and Germany in Ankara at the end of January for talks on Tehran's controversial atomic programme.

The West suspects Iran seeks to build nuclear weapons, while Tehran insists its programme aims only to meet the energy needs of a growing population.