The White House on Thursday called on Iran to ”come clean” about its nuclear activities and said a U.N. watchdog agency’s report raised ”very serious concerns” even though it found no evidence Tehran has a nuclear weapons program.

White House national security adviser Condoleezza Rice disputed Iranian suggestions that the report of the International Atomic Energy Agency laid ”to rest any concerns about what’s going on in Iran.”

”I think that’s, shall I say, an overstatement of the case,” Rice told reporters.

”The IAEA report made clear that the Iranians have been concealing, that they’ve not been truthful in the past. And I think the issue now is are they going to be truthful in the future? Are they going to come clean about what had been going on Iran, what is going on in Iran?” Rice asked.

The IAEA, in a report circulated on Monday, said Iran had a centrifuge uranium enrichment program for 18 years and a high-tech laser enrichment program for 12 years, both hidden from the United Nations.

It also said Iran produced small amounts of plutonium, usable in a bomb and with virtually no civilian uses, and conducted secret tests of enrichment centrifuges using nuclear material.

Despite Iran’s secretiveness and the activities possibly associated with weapons, the IAEA said there was no proof to date of an arms program. Iran has always denied the charge.

Rice said the international community should keep up the pressure given Iran’s track record of secrecy.

”The international community has an obligation, knowing now what we know about Iran’s behavior, past behavior, to make sure that anything that is signed on to with the Iranians takes account of that past, and really insists on performance from the Iranians # not promises from the Iranians,” she said.