Iran is likely to make a new announcement regarding its controversial nuclear program during a ten-day celebration to mark the 31st anniversary of the country's 1979 Islamic Revolution starting Monday.

Iran usually holds a demonstration of its scientific and technological achievements during the celebrations, running annually from February 1 to 11 and led by the country's religious leader, Ayatollah Khomeini.

In early February 2009, Iranian President Mahmoud Ahmadinejad announced the launch of the country's first domestically-built satellite into orbit.

This time he is likely to announce 20% uranium enrichment from 3.5%. Iran needs 20%-pure uranium for a Tehran research reactor. Iranian authorities also plan to launch three satellites and to hold large-scale military drills, thought to involve missile tests.

The festivities, known as the "Ten Days of Dawn" will culminate on February 11, the date when revolutionary forces led by Ayatollah Ruhollah Khomeini defeated pro-government troops in armed street clashes.

During the festivities, opposition forces might again gather for an attempt to revive demonstrations against alleged fraud in last year's Iranian presidential elections. The latest major unrest in the Iranian capital took place late last year during Ashura, a 10-day period of religious ceremonies.

The West suspects Iran of pursuing a secret nuclear weapons program, but the Islamic republic says it needs nuclear power solely for civilian purposes.

Under an international plan, Iran was to ship its low-enriched uranium to Russia and France for further enrichment and processing into fuel for power plants. Iran would not thereby be able to enrich uranium to make weapons.

Tehran disagreed, suggesting it could consider a simultaneous swap of its nuclear fuel for other uranium, but that the exchange would have to take place on its own territory.