The Bush administration renewed its criticism of Iran on Tuesday, saying a two-week suspension of international inspections of its nuclear facilities "is a continuation of a pattern of delay and deception and denial."
State Department spokesman Adam Ereli said, "It's time to come clean fully, unequivocally and completely."
But Mohamed ElBaradei (search), director of the International Atomic Energy Agency (search), took a softer line on Iran. "They understand they must come forward," the U.N. official said after a meeting with Deputy Secretary of State Richard Armitage.
Referring to the discovery of hidden research and development programs, ElBaradei told reporters getting to the bottom of Iran's program was "a work in progress."
He also reminded reporters that Iran had said it made "a strategic decision to come clean."
U.N. inspectors are due to return to Iran on March 27 after a two-week suspension. Ereli said it was "regrettable" that Iran had called off inspections for two weeks.
But, he said despite some differences among the 35 nations that are members, the IAEA Board of Governors had again insisted that Iran disclose all its programs.
ElBaradei is due to meet with President Bush on Wednesday. "The United States is very supportive of what we are doing," he said.
Iran suspended inspections last weekend after the U.N. agency adopted a resolution deploring recent discoveries of uranium enrichment equipment and other suspicious activities that Iran had failed to reveal. Iran's top nuclear negotiator, Hasan Rowhani, had described the IAEA resolution as "unfair and deceitful."
On Tuesday, in Tokyo for a meeting with Japanese Foreign Minister Yoriko Kawaguchi, he confirmed the inspectors would be permitted to return. "It is certain, and it will be without any conditions," said Rowhani, who also heads Iran's Supreme National Security Council (search).
Iran says its nuclear activities are designed to generate electricity. The Bush administration suspects Iran is developing nuclear weapons.