An unidentified International Atomic Energy Agency (IAEA) inspector disconnects the connections between the twin cascades for 20 percent uranium production at nuclear power plant of Natanz, some 300 km south of Tehran, on Jan. 20, 2014. (AFP photo)

TEHRAN, June 23 (Xinhua) -- Iran's atomic chief dismissed the U.S. demand for "zero enrichment" of uranium in the Islamic republic, Tasnim news agency reported Saturday.

Ali Akbar Salehi, head of the Atomic Energy Organization of Iran (AEOI), slammed the U.S. demand as a repetition of Washington's past mistakes.

Salehi made the remarks on Friday at the sidelines of the Oslo Forum in Norway, the leading international network of conflict mediation practitioners.

The nuclear negotiations between Iran and world powers that led to the 2015 Iran nuclear deal initially began on condition that the U.S. abandons the notion of zero enrichment, said Salehi.

He warned that the Middle East and the entire world will face a "dreadful" consequence if the nuclear agreement, officially known as the Joint Comprehensive Plan of Action (JCPOA), collapses under Washington's "unwise and baseless" decisions.

He also urged the European Union and other countries supporting the JCPOA to adopt practical steps to combat the U.S policies in this regard.

On Thursday, Iranian Foreign Minister Mohammad Javad Zarif said Iran will not negotiate with the United States, which fails to keep its word and moves to sabotage multilateral agreements one after another.