Britain, France, and Germany have warned they are prepared to reinstate United Nations-mandated sanctions on Iran if no diplomatic resolution is reached by the end of August, according to a joint letter obtained by AFP.
The letter, addressed to UN Secretary-General Antonio Guterres and the UN Security Council, states that the three European powers remain “committed to use all diplomatic tools at our disposal to ensure Iran does not develop a nuclear weapon” unless Tehran complies with the deadline.
The foreign ministers of France, Britain, and Germany—Jean-Noel Barrot, David Lammy, and Johann Wadephul—threatened to activate a “snapback mechanism” embedded in the 2015 nuclear deal, formally known as the Joint Comprehensive Plan of Action.
Under this provision, any party to the agreement can restore sanctions if Iran violates its commitments. The deal, which expires in October, was originally signed by the U.S., China, Russia, and the three European nations.
The ministers cited Iran’s suspension of cooperation with the International Atomic Energy Agency and its accumulation of uranium stockpiles exceeding 40 times the permitted limit under the JCPOA. “We have made clear that if Iran is not willing to reach a diplomatic solution before the end of August 2025, or does not seize the opportunity of an extension, E3 are prepared to trigger the snapback mechanism,” they wrote.
The warning follows heightened tensions after Israel launched a 12-day war against Iran in June, targeting its nuclear facilities, and the U.S. conducted airstrikes during the conflict. Iran subsequently halted all cooperation with the IAEA, though it later announced that the agency’s deputy chief would visit Tehran for discussions on a potential new cooperation framework.
The European ministers dismissed Iran’s claim that they lacked the legal authority to restore sanctions, calling the assertion “unfounded.” They emphasized that as JCPOA signatories, they were “clearly and unambiguously legally justified” in invoking UN resolutions to prohibit uranium enrichment and reimpose sanctions.
Despite the ultimatum, the E3 nations reiterated their preference for diplomacy. “The E3 remain fully committed to a diplomatic resolution to the crisis caused by Iran’s nuclear programme and will continue to engage with a view to reaching a negotiated solution,” the letter stated.
The standoff comes after former U.S. President Donald Trump withdrew from the JCPOA in 2018 and reimposed sanctions, while European signatories attempted to salvage the agreement. Iran has consistently denied seeking nuclear weapons, maintaining that its program is for peaceful purposes.