Sancerre, France ? Iran has slowly but steadily increased its ability to enrich uranium despite international calls to halt its nuclear activities, experts at the International Atomic Energy Agency say in a report released Tuesday.

The report, which became public in advance of a meeting next week by the agency’s board of governors, emphasized that Iran’s failure to answer inspectors’ questions about its nuclear activities made it impossible for the IAEA “to confirm the peaceful nature of Iran’s program.”

The report also noted that traces of plutonium had been found on storage barrels at a waste facility, in addition to a previously reported finding of highly enriched uranium at the site.

Iran had kept its nuclear program secret for more than 18 years, until 2002, and many questions remain unanswered about whether its effort had, or continues to have, a military goal. Highly enriched uranium is the fissile material used to make a nuclear bomb.

Iranian President Mahmoud Ahmadinejad did little to reassure world leaders Tuesday. He told a news conference in Tehran that there will be “the big celebration of Iran’s full nuclearization in the current year.”

Iran’s current calendar year ends March 20.

Iranian officials previously have said Tehran would have 3,000 centrifuges, used to enrich uranium, operating by the end of the Iranian year. Ahmadinejad said Tuesday that the goal is eventually to have 60,000. “We are at the beginning of a wave,” he said at the gathering, reported by Iran’s semiofficial news service, Irna.

While that goal is possible, it would appear to require a drastic acceleration in Iran’s program.

The IAEA inspectors are reluctant to make any predictions about the speed with which Iran might move ahead.

Inspectors have had limited information about Iran’s nuclear operations since Tehran reduced their access to nuclear facilities early this year.