WASHINGTON — The Bush administration went public Thursday with sensitive intelligence meant to show that North Korea spent years helping Syria build a covert facility for nuclear weapons before the plant was destroyed in an Israeli airstrike last year.
The disclosures offered a rare look at evidence gathered by U.S. and allied intelligence agencies and were part of a choreographed campaign by the administration to put pressure not only on North Korea and Syria, but also on other adversaries accused of pursuing nuclear weapons, including Iran.
The previously classified information included satellite images of the Syrian facility, photos of a man identified as a North Korean nuclear expert in Syria, as well as pictures taken by someone with access to the structure as it was being built.
The photos were presented in a glossy dossier that called attention to similarities between the Syrian plant, at a desert site called Al Kibar, and North Korea's nuclear reactor at Yongbyon.
The evidence left several questions unanswered, such as how Damascus would fuel the plant or manufacture bombs, and was greeted with skepticism by some nuclear experts and foreign officials.
U.S. intelligence officials acknowledged that they had not obtained evidence indicating Syria was working on nuclear weapons designs and had not identified a source of nuclear material for the facility.
In detailing the alleged North Korean-Syrian cooperation and the destruction of the plant, the Bush administration broke a long silence. U.S. officials confirmed the Israeli attack on the site and indicated that they had cooperated intensively with the Israelis on intelligence and policy issues. They denied any U.S. involvement in planning or executing the Sept. 6 strike.
To highlight the importance of the revelations, the administration sent three top officials to Capitol Hill to conduct closed-door briefings for several congressional committees. The officials included Director of National Intelligence J. Michael McConnell, CIA Director Michael V. Hayden and White House national security advisor Stephen Hadley.
As the briefings concluded, the White House issued a statement condemning North Korea and Syria and warning Iran that it should relinquish any nuclear weapons aspirations.
Syria responded by denouncing the charges as "false allegations." There was no immediate reaction from North Korea.
A senior Bush administration official said the timing of the intelligence disclosure was driven by a desire to strengthen the U.S. position in talks aimed at pressuring North Korea to provide a full accounting of its nuclear and proliferation activities.
Intelligence officials said North Korea appeared to have been helping Syria up until the facility was destroyed, and afterward helped it carry out damage assessments. If true, North Korea would be accused of continuing proliferation activities even as the United States was moving toward granting concessions, including removing North Korea from a list of nations that sponsor terrorism, as rewards for responsible behavior.
Few calls to end talks
Some have questioned whether the release was part of an effort by foreign policy hawks to undermine the talks. But there were few calls for ending them.
Administration officials vowed to push ahead in negotiations, and Sen. John McCain of Arizona, the presumed Republican presidential nominee, said the government should seek "an agreement that advances America's national interests in the full denuclearization of North Korea."
The White House hopes to pressure Syria not just over the alleged nuclear plant but also because of what the administration considers its destabilizing involvement in Lebanon, its support for terrorism, its role as a transit point for foreign fighters in Iraq and its political repression.
"If Syria wants better relations with the international community, it should put an end to these activities," the White House said.
The administration has been pressuring Iran over its nuclear program, which Iran denies is intended to produce nuclear weapons.
In a briefing with reporters, a senior U.S. intelligence official said that American spy agencies had been monitoring suspicious activity between North Korea and Syria for nearly a decade but that the information had been inconclusive until the CIA obtained dozens of photos taken by a hand-held camera.
The images include shots taken inside what appears to be a reactor -- with a grid of cylinders for control rods and refueling ports that are arrayed almost identically to those found at Yongbyon. Photos from outside the facility show a structure with similar roof lines, rows of windows and boxlike buildings matching the layout at Yongbyon.
The dossier distributed by the administration describes the facility as a gas-cooled, graphite-moderated reactor that was not configured to produce electricity and was ill-suited for research.