The head of Iran's Atomic Energy Organization says the country's underground uranium-enrichment facility "will be operational in the near future."
The "Kayhan" daily quoted Fereidoun Abbasi-Davani as saying 20 percent-enriched uranium can be produced at the Fordow nuclear enrichment plant.
The new facility at Fordow, an Islamic Revolutionary Guards Corps base near Qom, is dug deep into a mountain in what many Western governments believe is an attempt to protect the centrifuges from any possible attack.
Tehran announced last summer it would shift its production of higher-grade uranium to the site in defiance of international calls to halt uranium enrichment.
At the same time, Iran continues to use centrifuges to enrich uranium at its long-standing but less fortified facility in Natanz. Iran so far has enriched uranium to a 20 percent concentration -- more than the 4 percent level needed for nuclear power fuel but still short of the 90 percent level needed for nuclear warheads.
Western nations fear the process is aimed at making nuclear bombs -- a charge Iran denies.
A war of words between Washington and Tehran has increased recently, with Iran warning the United States not to send naval vessels through the strategic Strait of Hormuz.
Meanwhile, UN Secretary-General Ban Ki-moon called on both Iran and the United States to "do their best" to defuse tensions in the region, and resolve their differences through talks.
Ban also said it was ultimately up to Iran to prove its nuclear program was solely for peaceful purposes.
The UN chief also said he remained "concerned" over a recent report by the UN nuclear watchdog, the International Atomic Energy Agency, suggesting there was a military dimension to Iran's nuclear program.
compiled from agency reports