France, Germany and the UK, the countries, known as the E3, said on Saturday they were "deeply concerned" about Iran's plans to step up its enrichment of uranium, saying the move had "grave military implications." "We, the governments of France, Germany and the United Kingdom, are deeply concerned by Iran's announcement that it is preparing to produce uranium metal," read a statement by the troika. "Iran has no credible civilian use for uranium metal. The production of uranium metal has potentially grave military implications." Iran is committed to the global nuclear pact, known as the Joint Comprehensive Plan of Action (JCPoA), which prohibits producing or conducting research on uranium for 15 years, they added. The three countries went on to urge Tehran to halt the plans and recommit to the nuclear deal. The troika on Saturday warned Iran against starting work on uranium metal-based fuel for a research reactor, saying it contravened the 2015 nuclear deal. The UN nuclear watchdog and Tehran said on Wednesday that Iran had started the work, in the latest breach of its nuclear deal with six major powers as the country presses for a lifting of US sanctions. "We strongly encourage Iran to end this activity and return to full compliance with its commitments under the Joint Comprehensive Plan of Action (Iran nuclear deal) without delay, if it is serious about preserving this agreement," the three nations said in a joint statement. The three European nations earlier in the month had all urged Iran to stop enriching uranium to up to 20 percent. "We are deeply concerned by the commencement by Iran on the 4th of January of uranium enrichment up to 20 percent at the underground facility of the Fordow Fuel Enrichment Plant. "This action, which has no credible civil justification and carries very significant proliferation-related risks, is in clear violation of Iran's commitments under the Joint Comprehensive Plan of Action (JCPoA) and further hollows out the Agreement," a joint statement said. "We strongly urge Iran to stop enriching uranium to up to 20 percent without delay, reverse its enrichment program to the limits agreed in the JCPoA and to refrain from any further escalatory steps which would further reduce the space for effective diplomacy. "We remain in close contact with the other remaining JCPoA participants to assess how to best address Iran's non-compliance within the framework of the JCPoA," concluded the statement. — Agencies