Iran and Russia ink $25 billion nuclear deal as inspectors face access hurdles

Sanctions have pushed Moscow and Tehran to rely on each other for energy and technology. In September 2025, the two countries signed an agreement to build a new nuclear power plant in Iran.

The deal covers the Sirik site in Hormozgan Province, near the Strait of Hormuz. IRNA, Iran’s state news agency, reported the contract value at $25 billion. The units will have a combined capacity of about 5 gigawatts. This exceeds the capacity of the existing Bushehr complex, which will total under 3 gigawatts when finished.

Construction at the older Bushehr site continues alongside the new project. Rosatom, Russia’s state nuclear corporation, completed the first reactor there in 2013. Work on a second unit is more than 60 percent complete, with a target start date of 2029. A third unit is also under construction. Rosatom reported that 135 engineering and technical specialists returned to the site by October 11, after many were evacuated following the start of the US-Iran war in February.

The legal framework for this cooperation is the Comprehensive Strategic Partnership Treaty, which entered into force in October 2025. A practical roadmap is the intergovernmental Cooperation Plan for 2024-2026, approved in September 2024. For Russia, the partnership offers commercial revenue and a way to maintain influence in the Middle East. For Iran, it provides access to nuclear technology, expertise, and fuel supplies.

Analysts suggest the balance of power in the relationship favors Moscow. Nikita Smagin of the Carnegie Endowment for International Peace wrote in November 2025 that the balance is shifting in Russia’s favor. He noted that Iran is in dire need of investment and Russia remains one of the few available sources. Dmitry Kovchegin and Arkady Mil-Man of the Institute for National Security Studies in Israel described Moscow’s policy as a calculated balancing strategy in a June analysis. They said Russia uses limited assistance and mediation services to improve relations with the United States while rhetorically condemning military escalation.

International oversight of these activities has weakened. The International Atomic Energy Agency published a report on June 4. It stated that inspectors visited Bushehr from June 1 to 3. However, they could not carry out inspections at other declared nuclear sites during that period. These sites include four uranium enrichment facilities. The IAEA could not verify the status of nuclear material at these locations or confirm whether Iran suspended enrichment, reprocessing, and heavy-water-related activities as required by UN Security Council and IAEA resolutions.

The expansion of nuclear ties coincides with broader military and economic integration. A 2025 analysis by the Center for Naval Analyses found that Russia and Iran expanded military contacts and arms transfers since Russia’s 2022 invasion of Ukraine. The two countries have also pursued new trade agreements and closer banking links. The CNA researchers noted that competition between the two economies could constrain the longer-term growth of their economic relationship.

Nonproliferation specialists have raised concerns about transparency. Some argue that civilian nuclear cooperation has consequences beyond electricity generation. Iran has accumulated uranium enriched to 60 percent. This level is not weapons-grade, but it can be enriched further to around 90 percent, the level generally associated with nuclear weapons. The Arms Control Association stated in June 2025 that enrichment to 60 percent has no civil justification and puts Iran in a better position to quickly produce enough weapons-grade material for a bomb.