Iran's controversial president, Mahmoud Ahmadinejad, plans to retire from politics after the end of his term in 2013.

Ahmadinejad, who was re-elected two terms in a row but faced a backlash in 2009 after thousands of protesters took to the streets to contest the presidential election results, announced his plan in an interview with Germany's Frankfurter Allgemeine Sonntagszeitung.

"Eight years are enough," the German newspaper quoted him as saying.

Ahmadinejad who studied engineering at Iran University of Science and Technology (IUST) said he would return to his previous area of expertise. "I am planning to return to science," he explained.

No third term

Despite revealing he might engage politically at university he ruled out the possibility of creating his own political party.

Ahmadinejad cannot run for a third consecutive term in office, meaning Iranians are set to elect a new president in 2013.

In the interview the president also insisted Iran has co-operated with the International Atomic Energy under his administration.

He blamed European and United States interference for its troubled relationship with the UN nuclear agency but reiterated previous assertion that the Parchin military facilities would not be open for inspection by the IAEA.

Ahmadinejad is the main political leader of the Alliance of Builders of Islamic Iran, a coalition of conservative political groups.

While Ahmadinejad and Iran's Supreme leader Ali Khamenei continue to put out a united front in public, the relationship between the two has become increasingly tense as they become involved in a struggle for power.

The president's loyalists lost ground during the country's last parliamentary election in March.