Tehran and Moscow have signed a $25bn deal to build four nuclear power reactors in southern Iran, according to Iranian state media.

Friday’s announcement comes as the United Nations Security Council is expected to vote on a China- and Russia-backed resolution seeking delay, for at least six months, in the reimposition of international sanctions against Iran under the so-called “snapback mechanism” over its nuclear programme.

Iran’s IRNA news agency reported that the deal covers the construction of four new units on a 500-hectare (1,235-acre) site in the city of Sirik in the southern Hormozgan Province, which sits across the Gulf from the United Arab Emirates and Oman.

IRNA said the Generation III power reactors would generate 5GW of electricity.

Russia’s state nuclear agency Rosatom had announced that it had signed a memorandum of understanding on Wednesday in Moscow on the construction of small nuclear power plants in Iran, but gave no number.

Iran, which suffers power shortages at times of high demand, currently has one operating nuclear power plant, in the southern city of Bushehr. Also built by Russia, it has a capacity of 1 GW.

Russia maintains close relations with Iran. Moscow roundly condemned the United States and Israeli strikes on Iranian nuclear sites in June.

Israel said at the time, without providing evidence, that Iran was on the verge of acquiring nuclear weapons. Western states have long suspected Tehran of using its nuclear energy sites as a cover.

Iran insists it has no such intention. President Masoud Pezeshkian reiterated at the UN General Assembly earlier this week that Tehran will “never seek to build a nuclear bomb”.

Russia has also opposed the reimposition of punishing UN sanctions against Iran, and has backed more diplomacy to keep the 2015 nuclear deal alive.

The “snapback mechanism” of the Iran sanctions is set to take effect by the end of Saturday and is being pushed by France, Germany and the United  Kingdom.