The UN nuclear watchdog said Tuesday that a team of its inspectors was in place in Iran to monitor Tehran's plans to start enriching uranium to higher levels. "I can confirm that officials are there in Natanz today," said a spokesman for the International Atomic Energy Agency. "What they find and assess will be reported to the board," the spokesman added. Iran said earlier it has started the process of producing 20 percent enriched uranium at a plant in the central city of Natanz, defying world powers who have warned of new sanctions unless the Islamic republic halts its nuclear drive. "From today we have started the 20 percent enrichment in a separate cascade in Natanz," Iran's atomic chief Ali Akbar Salehi told the official IRNA news agency.