Iranian President Mahmoud Ahmadinejad on Saturday called the September 11 attacks on the United States a "big fabrication" that was used to justify the US war on terrorism, the official IRNA news agency reported.
Ahmadinejad, who often rails against the West and Israel, made the comment in a meeting with Intelligence Ministry personnel.
It came amid escalating tension in the long-running dispute between Iran and the West over Tehran's nuclear program, with the United States pushing for new UN sanctions against the major oil producer.
Ahmadinejad described the destruction of the twin towers in New York on September 11, 2001 as a "complicated intelligence scenario and act," IRNA reported.
He added: "The September 11 incident was a big fabrication as a pretext for the campaign against terrorism and a prelude for staging an invasion against Afghanistan." He did not elaborate.
Nearly 3,000 people died in the hijacked airliner attacks on New York and Washington, which were carried out by al Qaeda operatives.
In January, Ahmadinejad termed the September 11 attacks "suspicious" and accused the West of seeking to dominate the Middle East.
Ahmadinejad, who has called for Israel to be wiped off the map, was re-elected in a disputed presidential vote last June that stirred the largest display of internal unrest in the country since the 1979 Islamic revolution.