"I would like to say absolutely clear and directly that acquiring some false topicality the theme of the IAEA work on Section T of the Joint Comprehensive Plan of Action (JCPOA) over the Iran nuclear program has no topicality for us although it is a talking point now," Ryabkov told the Tass news agency on Saturday.

Section T bans “activities which could contribute to the development of a nuclear explosive device”. It lists examples such as using computer models that simulate a nuclear bomb, or designing multi-point, explosive detonation systems.

Moscow says that the IAEA "has not been authorized to carry out such inspections (inspection of Iran’s military sites) and cannot be tasked because Section T highlights the issues out of the agency’s competence," Ryabkov said.

Unlike many other parts of the deal, the provision makes no mention of the IAEA or specifics of how it will be verified. Russia says that means the IAEA has no authority over it. Western powers and the agency disagree.