President Bush has offered U.S. assistance to Iran after three earthquakes there killed at least 66 people.
But in his comments on Friday in Cancun, Mexico, Mr. Bush also said that the world rejects what he called Iran's desire to have a nuclear weapon. He said Iran would pose a serious threat to the world with such a weapon.
Tehran has repeatedly said its nuclear program is for peaceful purposes.
Three earthquakes struck western Iran overnight Thursday, flattening homes, destroying villages and injuring more than a thousand people.
The quakes and aftershocks hit the towns of Doroud and Boroujerd as well as many villages in between.
Iran's official news agency, IRNA, said Iranian President Mahmoud Ahmadinejad has instructed the Interior Ministry to mobilize all available resources to the stricken region.
The first quake hit shortly after 11 p.m. local time on Thursday. The US Geological Survey says the strongest of the three quakes, a magnitude six-point-one, struck just before dawn friday (0117 Hours UTC).
Earthquakes are a common occurrence in Iran, which is located on several major seismic fault lines. In 2003, a powerful quake flattened the ancient city of Bam, killing at least 26-thousand people.