BERLIN -- Germany, France and Britain pressed Iran on Saturday to back off the latest planned violation of its 2015 nuclear deal with world powers, saying that Tehran has "no credible civilian use" for uranium metal.

The International Atomic Energy Agency said Thursday Iran had informed it that it had begun installing equipment for the production of uranium metal. It said Tehran maintains its plans to conduct research and development on uranium metal production are part of its "declared aim to design an improved type of fuel."

Uranium metal can also be used for a nuclear bomb, however, and research on its production is specifically prohibited under the nuclear deal -- the so-called Joint Comprehensive Plan of Action -- that Tehran signed with Germany, France, Britain, China, Russia and the United States in 2015.

Since the unilateral American withdrawal from the deal in 2018, the other members have been working to preserve the accord. Iran has been using violations of the deal to put pressure on the other signatories to provide more incentives to Iran to offset crippling American sanctions re-imposed after the U.S. pullout.

A joint statement from the German, French and British foreign ministries said they are "deeply concerned" by the latest Iranian announcement.

"Iran has no credible civilian use for uranium metal," it said. "The production of uranium metal has potentially grave military implications."

"We strongly urge Iran to halt this activity, and return to compliance with its JCPoA commitments without further delay if it is serious about preserving the deal," the statement added.

The ultimate goal of the deal is to prevent Iran from developing a nuclear bomb, something Iran insists it does not want to do.

President-elect Joe Biden, who was vice-president when the deal was signed during the Obama administration, has said he hopes to return the U.S. to the deal.