U.S. Defense Secretary Mark Esper has hinted that Iran might be nearer to an opportunity for new talks despite Tehran's latest move away from adherence to international curbs on its nuclear activities.
The statement came hours after Tehran told the European Union overnight that it had abandoned limits on research and development set out in its 2015 nuclear deal with world powers, describing it as a "third step" to scale back nuclear commitments since the United States withdrew from the agreement last year.
Speaking at a think tank in London on September 6, Esper said there might soon be room for talks over Iran's nuclear and missile programs.
"It seems in some ways that Iran is inching toward that place where we could have talks and hopefully it'll play out that way," Esper said at the Royal United Services Institute.
Meanwhile, U.S. Secretary of State Mike Pompeo told Kansas City radio station KCMO that Iran's latest reduction in commitments to the nuclear deal was "unacceptable," according to AFP.
On Twitter, Pompeo pressed Britain, France, and Germany to "take decisive actions to stop Iran's nuclear extortion."
British Defense Secretary Ben Wallace, who was meeting with Esper on September 6, said he he did not want to speculate about Tehran's intention but would judge it by its actions, according to Reuters.
If there is a deal to be made with Iran, he added, Britain "will help the United States along that path."
In Berlin, a spokesman for the German Foreign Ministry called on Iran "not to escalate the situation further."
"Considering the ongoing efforts to deescalate, this announcement [from Tehran] is not the right signal," the spokesman added.
A spokeswoman for EU foreign-policy chief Federica Mogherini noted that the bloc's commitment to the nuclear agreement "depends on full compliance by Iran," and urged Tehran not to commit further violations.
In comments carried by Iran's state news agency, IRNA, Foreign Minister Mohammad Javad Zarif said that "it is time for Europeans to stop...failing to fulfil their obligations and to fulfil the commitments they have made."
Earlier in the day, Zarif informed the bloc of Iran's resumption of research in a letter to Mogherini, who has sought to salvage the nuclear deal on behalf of its European signatories.
Experts describe the limits on R&D as one of the so-called Joint Comprehensive Plan of Action (JCPOA)'s main principles.
"Due to the impacts of America's exit from the JCPOA and the European countries' failure to fulfill their commitments under the JCPOA and the communiques of the joint commission, the Islamic Republic of Iran will suspend all of its JCPOA commitments with regards to nuclear research and development," Iran's Press TV quoted the letter as saying, according to a Foreign Ministry spokesman.
Iranian media say the country's Atomic Energy Organization will detail Tehran's next step at a press conference on September 7.
The acting head of the UN's nuclear watchdog, the International Atomic Energy Agency, is set to travel to Iran this weekend to meet high-level officials, the organization said.
Cornel Feruta's visit "is part of ongoing interactions between the IAEA and Iran," a statement said, adding that this included the IAEA's verification and monitoring in Iran under the 2015 nuclear deal.
Iranian President Hassan Rohani said on September 4 that Iran would lift "all limitations" on its development of centrifuges on September 6, adding that the country will do "whatever is needed for enriching uranium in an accelerated way."
But he also pledged that the new steps would be "peaceful, under surveillance of the UN nuclear watchdog, and reversible" if the European signatories to the deal kept their promises.
U.S. President Donald Trump recently teased the possibility of a meeting with Rohani at the upcoming UN General Assembly in New York.
On September 5, France urged Iran to "refrain from any concrete action that is not in line with its commitments and that may hinder deescalation efforts."
Britain’s Foreign Office called Tehran's plan to suspend limits on its nuclear research and development "deeply concerning."
Under the JCPOA with world powers -- including China, Britain, France, Germany, and Russia -- Iran is allowed to operate restricted quantities of first-generation centrifuges.
Enriched uranium can be used to make fuel for reactors but also nuclear weapons, and more advanced centrifuges could accelerate Iran's ability to produce material for a potential nuclear bomb.
Trump campaigned hard against the agreement and has pursued a policy of "maximum pressure" against Tehran since pulling out of the accord in 2018, reimposing tough sanctions that have battered the Iranian economy and currency.
Iran reportedly began breaching the JCPOA in July, calling it a response to U.S. actions.
France last week proposed offering Iran a $15-billion credit line until the end of the year -- guaranteed by oil -- in return for Tehran adhering to the terms of the nuclear pact, but U.S. officials signaled they wouldn't grant sanctions waivers to accommodate such an arrangement.
U.S. authorities have further tightened their Iran sanctions this week, including specifically targeting Iran's nuclear agency and research institutions.
In a tweet on September 6, Zarif accused the United States of "rouge [sic] behavior" and "economic terrorism" against Iran, China, Russia, Cuba, and Syria.