WASHINGTON  A week after American intelligence agencies reported that Iran halted work on a covert nuclear weapons program in 2003, the Bush administration expressed confidence on Tuesday that it had rallied international support to intensify diplomatic and economic pressure on Iran’s government.

On a day that Iran’s president, Mahmoud Ahmadinejad, called last week’s assessment “a step forward,” President Bush responded by demanding that Iran disclose its weapons program to international inspectors and end its continuing uranium-enrichment program. Iran has denied it ever had a military program, and has insisted that it is enriching uranium for civilian energy use.

“We believe Iran had a secret military weapons program,” Mr. Bush said at the White House. “And Iran must explain to the world why they had a program.”

After a week of conflicting statements, senior administration officials now increasingly express chagrin that last week’s National Intelligence Estimate, a document representing the consensus views of 16 intelligence agencies, incorrectly focused on the suspension of a secret weapons program and not on the accelerated effort to enrich uranium. That undercut the administration’s main rationale for confronting Iran, and left the administration seeking to regain the diplomatic initiative for continued sanctions.