TEHRAN — Iran will soon unveil "big new" nuclear achievements, President Mahmoud Ahmadinejad said Saturday while reiterating Tehran's readiness to revive talks with the West over the country's controversial nuclear program.

Ahmadinejad spoke at a rally in Tehran as tens of thousands of Iranians marked the 33rd anniversary of the Islamic Revolution that toppled the pro-Western monarchy and brought Islamic clerics to power.

Ahmadinejad did not elaborate on the upcoming announcement but insisted Iran would never give up its uranium enrichment, a process that makes material for reactors as well as weapons.

The West suspects Iran's nuclear program is aimed at producing atomic weapons, a charge Tehran denies, insisting it's geared for peaceful purposes only, such as energy production.

Four rounds of U.N. sanctions and recent tough financial penalties by the U.S. and the European Union have failed to get Iran to halt aspects of its atomic work that could provide a possible pathway to weapons production.