IAEA: Iran’s stock of uranium enriched to near weapons grade has grown sharply since it announced a dramatic acceleration in December and there has been no progress on resolving outstanding issues, two reports by the U.N. nuclear watchdog showed on Wednesday.

The stock of uranium enriched to up to 60% fissile purity, close to the roughly 90% of bomb grade, has been a long-standing concern for Western powers, which say there is no civil justification for enriching uranium to such a high level. Iran says it seeks only peaceful nuclear energy.

While U.S. President Donald Trump’s administration has said it plans to pressure Iran over its nuclear program, the International Atomic Energy Agency has said time is running out for diplomacy to impose new restrictions on Iran’s activities.

Two quarterly reports sent by the IAEA to member states showed that while the stock of 60% material has grown by around half, there has been no real progress on resolving long-running issues with Iran, including the unexplained presence of uranium traces found at undeclared sites.

“The significantly increased production and accumulation of high enriched uranium by Iran, the only non-nuclear weapon state to produce such nuclear material, is of serious concern,” the IAEA said in a passage that, unusually, was included in both reports.

The stock of uranium refined to up to 60% in the form of uranium hexafluoride grew by 92.5 kilograms in the past quarter, to 274.8 kilograms, one of two confidential IAEA reports said.

That is enough in principle, if enriched further, for six nuclear bombs, according to an IAEA yardstick. There is enough for more weapons at lower enrichment levels.

One of the reports also spelled out the lack of progress on the outstanding issues such as explaining the uranium traces, which the IAEA has been asking the Islamic Republic to do for years.

“Iran states that it has declared all of the nuclear material, activities and locations required under its Safeguards Agreement. This is inconsistent with the Agency’s assessments of the unexplained nuclear-related activities that took place at all four of the undeclared locations in Iran referred to above,” the report said.

“The Agency is, therefore, at an impasse with regard to resolving these outstanding safeguards issues.” VOA/SP