The United States said yesterday that Iran is "moving in the wrong direction" after the Islamic republic announced it has successfully enriched uranium for the first time.

Iran's announcement had heightened concerns in the international community about the country's nuclear program, White House spokesman Scott McClellan told reporters during a trip by President George W. Bush to Missouri.

Gholamreza Aghazadeh, Iran's Atomic Energy Organization, confirmed on Tuesday that Iran had enriched uranium to a level used in nuclear power plants. The pilot enrichment plant in Natanz, south of Tehran, started working on Monday, he said.

Iranian President Mahmoud Ahmadinejad declared earlier that his country was poised to enter the world's "nuclear club".

"Iran will soon join the club of countries that have nuclear technology," Iran's state-run television quoted Ahmadinejad as saying in a speech.

The United States has accused Iran of trying to develop nuclear weapons under the cover of civilian nuclear programs. However, Iran has said its nuclear programs are for civil purposes only.