An anti-nuclear rally September 24, 2009 in Washington, DC.(Alex Wong/Getty Images)
The statement came a day after U.S. President Barack Obama demanded that Iran come clean about its nuclear programme or face "sanctions that bite" after the disclosure of the new uranium enrichment plant under construction south of Tehran.
"This new plant, God willing, will soon become operational and will make the enemies blind," Mohammad Mohammadi-Golpayegani, who heads Khamenei's office, said, according to the semi-official Fars News Agency.
Also on Friday, Iranian President Mahmoud Ahmadinejad said the facility, which has sharpened international concern over Tehran's nuclear ambitions, was legal and open for inspection by the U.N. International Atomic Energy Agency.
He said the facility was around 18 months from starting operations and that Western powers would regret accusing Iran of hiding it.
Mohammadi-Golpayegani, a cleric, said the construction of the plant was a sign of Iran being at the "summit of power", Fars reported. He was speaking at a ceremony marking the start of the 1980-88 Iran-Iraq war.
