Iranian President Mahmoud Ahmadinejad trumpeted on Wednesday major advances in the Islamic Republic's nuclear program, in a move likely to further raise the stakes in its tense stand-off with the West.

"I am grateful to the Almighty...for these great achievements we are offering to the people of Iran and all humanity," he said at a research reactor in northwest Tehran.

In an event that was a startling mix of religious ceremony and scientific procedure, Ahmadinejad presided over the loading of Iran's first domestically produced nuclear fuel rods into the research reactor, joining scientists as they intoned Islamic prayers after each stage of the process.

He then took to the stage at the reactor's conference hall to announce that a "new generation of Iranian centrifuges" had been installed and put into operation at the country's main uranium enrichment facility at Natanz in central Iran. He said this brought the number of Iran's operating centrifuges for nuclear enrichment up to 9,000 from 6,000.