WASHINGTON - The United States said Monday that Iran's uranium enrichment work at a new site is a "further escalation" in the nuclear showdown with the international community.
Iran announced over the weekend that the Fordo plant near the city of Qom will be inaugurated soon and will have the capacity to produce uranium enriched to 20 percent as well as 3.5 percent and 4.0 percent.
"If they (Iranians) are enriching at Fordo to 20 percent, this... is a further escalation of their ongoing violations with regard to their nuclear obligations," State Department spokeswoman Victoria Nuland said.
"We call on Iran once again to suspend enrichment activities, cooperate fully with the IAEA and immediately comply with all Security Council and IAEA board of governors resolutions," Nuland told reporters.
In Vienna, the UN International Atomic Energy Agency said it "can confirm that Iran has started the production of uranium enriched up to 20 percent... in the Fordo Fuel Enrichment Plant."
In a statement, IAEA spokeswoman Gill Tudor said that "all nuclear material in the facility remains under the agency's containment and surveillance."
Nuland added: "This development, given their track record and what the IAEA inspectors have been able to report, it's not a surprise to us what we're hearing."
The Islamic republic admitted the existence of the facility in 2009 and earlier reports from the IAEA had said that Iranian scientists were preparing the facility to begin operations.
Iran, which insists its nuclear program is for exclusively peaceful purposes, has repeatedly said it will not abandon uranium enrichment despite four rounds of UN Security Council sanctions demanding Tehran desist.
While nuclear energy plants need fuel enriched to 3.5 percent, Iran says the 20-percent enriched uranium is needed for its Tehran research reactor to make isotopes to treat cancers.
Western powers reject this, believing Iran has been researching ways to develop and deliver nuclear weapons, and have piled on sanction after sanction to try to halt the work.
Nuland said that when uranium enrichment is raised to 20 percent, "it generally tends to indicate that you're enriching to a level that takes you to a different kind of a nuclear program."