Iran has taken another step in its ability to enrich uranium, Mohamed ElBaradei, director-general of the International Atomic Energy Agency (IAEA), said in Washington's Georgetown University on Monday, the Washington Post reported on Tuesday.

ElBaradei said that Iranian technicians had pieced together a second line, or cascade of 164 centrifuges, and are days away from using the cascade to enrich uranium, the report said.

"It is in place and ready to go," ElBaradei was quoted by the report as saying.

The new cascade is considered a political move by Iranian officials who are hoping to send a defiant message to the U.N. Security Council, as it weighs possible sanctions against the country, the report said.

Moreover, it would still take many years for Iran to produce weapons-grade uranium using the other 164-centrifuge cascade it is currently operating, and U.S. intelligence officials believe that Teheran is at least four years away from gaining the technical capability for a single weapon, the report added.

The United States has been seeking to impose sanctions on Iran through the U.N. Security Council on the grounds that Tehran is developing a nuclear-weapons program under the garb of a civilian-use program. However, Iran has said that its nuclear program is for peaceful purposes only.

Iran has said that it wants to hold talks with Europe, Russia, China and the United States, but it will not suspend its nuclear work as a prerequisite.