Tehran’s government “indicates that Iran’s uranium reserves are much larger than previously estimated,” wrote the authors of the report, who work at the Paris-based Nuclear Energy Agency and Vienna-based International Atomic Energy Agency. The country may almost quadruple ore production to 71 tons this year, according to the report. Unlike other parts of the nuclear-fuel cycle — the sprawling industrial process that concentrates uranium isotopes into fuel for energy — upstream mining activities are not frequently audited. IAEA inspectors track enriched uranium worldwide at gram levels because the material can also be used in weapons, but uranium ore can be mined and traded with fewer regulations. While Iran has always maintained its nuclear program is peaceful, in 2015 world powers negotiated caps on its work in exchange for sanctions relief. US President Donald Trump left that agreement — which included IAEA safeguards on Iranian mining activities — in May 2018 and reimposed stringent penalties on Iran’s economy. Since returning to office, Trump has said he wants a new nuclear agreement with Iran and has raised the threat of military action if Tehran doesn’t join direct talks to strike an accord soon. On Monday Iranian officials said they are ready for negotiations with the US if they’re mediated by Oman.