Iran's recent claim it was conducting research and tests on a more sophisticated type of nuclear enrichment centrifuge could significantly speed the process of making fuel for either electrical plants or bombs, analysts familiar with the technology said.

Iranian President Mahmoud Ahmadinejad told students Wednesday that the Islamic republic was testing the P-2 centrifuge — a more sophisticated type. A day earlier, he trumpeted Iran's success in enriching uranium using a less-sophisticated type of centrifuge.

"Our centrifuges are P-1 type. P-2, which has quadruple the capacity, now is under the process of research and test in the country," Ahmadinejad told the students in Khorasan in northeastern Iran.

His comments were subsequently posted on the official presidential Web site.

Iran's move to enrich uranium has come in defiance of demands from the United States, Europe and the U.N. nuclear watchdog agency.

The current centrifuges that Iran has used to do small-scale enrichment are considered an inferior model, said David Albright, a former U.N. inspector and head of the Institute for Science and International Security.

But Iran also is known to have received plans for the German-made P-2 centrifuges through a black-market network run by A.Q. Khan, considered the father of Pakistan's nuclear bomb. The P-2 centrifuges, more sophisticated and reliable, presumably would make it easier for Iran to ramp up the production of enriched uranium.

Ahmadinejad did not provide any details in his speech to the students. But his statement was the first time Iran has said officially it was seeking to develop the more advanced P-2 centrifuges as it continues to forge ahead with its nuclear development plans.

The United Nations has demanded Iran give up uranium enrichment amid accusations from the United States and Europe that the country seeks to develop nuclear weapons. Tehran denies those claims, saying the aim of its nuclear program is to generate electricity.

The Bush administration has said it had a "number of tools," including a military option, if Tehran did not cease uranium enrichment activities.

On Monday, Iran said threats would not affect its decision over whether to continue its nuclear program, state media reported.

"Threats are not effective," the television quoted Ali Larijani, Iran's top nuclear negotiator, as saying.

Last month, the U.N. Security Council demanded that Iran stop all enrichment activity by April 28 because of suspicions the program really aims to make weapons. But Iran has rejected the demand and announced last week that, for the first time, it had enriched uranium with 164 of the less-sophisticated P-1 centrifuges.

Last week, Larijani made no concessions during talks with Mohamed ElBaradei, the U.N. nuclear agency chief, who was trying to head off a confrontation with the Security Council while visiting Tehran.

Meanwhile, the state news agency also quoted Parviz Fattah, Iran's energy minister, as saying the government has plans to build 20 nuclear power plants.

Iran says it is enriching uranium to a low degree to be used as fuel for generating power in a nuclear power reactor. Higher-level enrichment makes uranium suitable for a nuclear bomb, but Western experts familiar with Iran's program say the country still is far from producing weapons-grade uranium.