The head of Iran's nuclear programme Ali Akbar Salehi will meet Russian energy officials Tuesday as the two countries prepare to sign a deal for two additional nuclear power plants, Russia's Rosatom said.

A meeting between state nuclear agency Rosatom and the head of the Atomic Energy Organisation of Iran, Ali Akbar Salehi, will take place this afternoon, a Rosatom spokesman told AFP.

"At the end of the meeting they will sign several documents," he said, without specifying whether the signing concerns an agreement to construct Russian nuclear reactors in Iran.

Salehi told IRNA news agency at the weekend that he will travel to Moscow to "sign an agreement for the construction of new nuclear power plants."

The so-called Bushehr-2 project involves two new nuclear reactors in Bushehr, where Russia has already launched a 1,000 megawatt reactor in 2013.

Rosatom said in June that the contract for additional reactors would be signed before the end of the year and they would be located at the same site on the Persian Gulf coast.

Iran plans to build 20 more plants in the future, including four in Bushehr, to decrease its dependence on oil and gas.

Tehran has been locked in thorny nuclear talks with six world powers, including the United States and Russia, with pressure mounting ahead of a November 24 deadline for a lasting deal to be clinched.

A particularly sensitive issue is Iran's ability to enrich uranium, which Tehran argues is needed to power Bushehr but Israel and Western powers fear will be used to make an atomic bomb.

On Sunday, US Secretary of State John Kerry met Iranian Foreign Minister Mohammad Javad Zarif in the Gulf sultanate of Oman to try to narrow differences ahead of the deadline.