WASHINGTON — The White House does not want the public to know that in May 2003, the Iranian Foreign Ministry floated the prospect of a wide-ranging dialogue with America on everything from uranium enrichment to anti-Israel terrorism.

At least this is what a former Middle East director of the National Security Council, Flynt Leverett, is saying after the CIA’s publication review board would not approve an op-ed he wrote, which was slated to run this week in the New York Times.

As a former CIA Syria analyst, Mr. Leverett is required to submit his written work to the board to guarantee that he does not publish classified information. But Mr. Leverett, who has met on occasion with senior Iranian officials since he left government, says he cannot publish this week’s piece because of political pressure from the White House.

Oddly enough, the CIA’s censors had already allowed the former analyst to publish the material. In a January 24 Times op-ed, “The Gulf Between Us,” Mr. Leverett wrote: “The Iranian Foreign Ministry sent Washington a detailed proposal for comprehensive negotiations to resolve bilateral differences. The document acknowledged that Iran would have to address concerns about its weapons programs and support for anti-Israeli terrorist organizations.”

The passage is similar to Mr. Leverett’s description of the Iranian offer in a longer paper for the Century Foundation published last month, which the agency’s publication review board also approved. Indeed, Mr. Leverett used similar words yesterday at a press conference at which he was introduced as a “Republican dissident” and thronged with well-wishing critics of the president’s foreign policy.

But it appears that for the CIA and the National Security Council, discussing the 2003 Iranian offer in the Times again would compromise state secrets. “In the interagency review, it was determined that there was classified material,” a spokesman for the CIA, Tom Crispell, said.

For Mr. Leverett, the fact that the information was censored is evidence of a neoconservative conspiracy. “It is an abuse of the prepublication review process to silence critics,” he said at the press conference at the New America Foundation, calling his case “unprecedented.” He went on to say that he believed that three senior National Security Council officials — Meghan O’Sullivan, Michael Doran, and Elliott Abrams — intervened personally to silence him.

A senior fellow at the foundation, Steven Clemmons, said that in talking with a senior intelligence official, he learned that the only way the White House would have censored the piece is if its publications could endanger current negotiations with Iran, or if Vice President Cheney himself had personally intervened.

Not so, a National Security Council spokesman, Gordon Johndroe, said yesterday. “These decisions on classifications are made by career staff. The career staff, who have worked for multiple administrations, made a determination that certain portions of the Op-Ed contained classified information. They returned this to the publication review board and followed standard procedure, “Mr. Johndroe said. When asked whether any of the officials Mr. Leverett named had a hand in inking out whole paragraphs of his submission, Mr. Johndroe said, “They do not make that determination.”

Another administration official, however, said that after the publication of Mr. Leverett’s longer paper for the Century Foundation, the National Security Council asked the chairman of the CIA’s publication review board, Richard Puhl, why it was not consulted when the board was reviewing the paper. Mr. Crispell said yesterday that it was a mistake not to ask for the National Security Council’s input on the earlier publications from Mr. Leverett.”This has nothing to do with politicization, or pressure from other government agencies. Their sole criteria is to protect classified information,” he said.

A lawyer who works with former CIA employees and the agency’s publication review board, Mark Zaid, said yesterday that Mr. Leverett’s case is not unprecedented but is part of a wider pattern. “The fact is that this sort of thing is happening more and more,” Mr. Zaid said. He added that he has encountered situations where the review board has widely distributed work to other people in the intelligence community and political appointees. He said he has also had the board challenge his clients on the basis that a series of unclassified facts placed together in a certain way could comprise classified information as well.

Mr. Leverett says a senior Iranian official confirmed to him personally “the seriousness of the offer” from May 2003 after he left government that summer. At the time, the Iranian press reported a meeting between Mr. Leverett — then retired — and the commander of the Iranian Revolutionary Guard, Mohsen Rezai, as if it were an official meeting.

Not all of Mr. Leverett’s old colleagues, however, agree that the Iranians were serious at the time about resolving their differences with America. A former Pentagon Iran analyst, Michael Rubin, said yesterday that the Swiss ambassador to Tehran who conveyed the offer to the State Department, Tim Guldimann, would “sometimes insert himself to construct proposals where proposals did not exist.”