WASHINGTON (CNN) -- U.S. intelligence officials will tell members of Congress on Thursday that North Korea was helping Syria build a nuclear facility, according to a source familiar with internal administration discussions.
Israeli soldiers in the Golan Heights look toward Syria on September 7, 2007, a day after an Israeli airstrike.
The facility in question was bombed by Israeli planes in September.
The United States and Israel have refused to comment on what the target of the strike was.
Some members of Congress have demanded to know what information the administration has about the incident.
Thursday's briefings to intelligence, foreign relations and armed services committees in both chambers of Congress are intended to show that the building hit was a North Korean-designed reactor being built with assistance from Pyongyang, the source said.
It is less clear whether North Korea had provided or was about to provide essential fuel components to Syria, according to the source.
Syria's ambassador to the United States criticized the Bush administration for the plan.
"This will be a ridiculous and pathetic charade," Imad Moustafa told CNN, adding that Syria has never had any nuclear project.
"All the accusations are absurd and preposterous," he said.
Moustafa told CNN the briefing was motivated by a constituency that is angry about the nuclear negotiations the United States is holding with North Korea and that is targeting Syria to help make its case.
"This is exactly the same story as Iraq and its weapons of mass destruction," he said. "There is a proven record of this administration to fabricate lies."
The briefings could complicate the six-party talks at which the United States and other major world powers are trying to get North Korea to give up its nuclear ambitions. Pyongyang has resisted disclosing its proliferation activities.
The United States has softened its demand that North Korea publicly admit to having a program to develop highly enriched uranium and to having provided Syria with nuclear technology, key questions that have left the negotiations stalled for months.
Officials said the United States concluded that it is more important to get a handle on the program than to have North Korea "confess" past nuclear sins.
The original agreement in the six-party talks did not deal with proliferation, but Secretary of State Condoleezza Rice said last week that it was important to do so "in light of some recent concerns about North Korean activities in proliferation."
"Syria is most certainly an issue in proliferation," she said, adding, "We have several nonproliferation questions on the table about North Korea."
State Department spokesman Sean McCormack said, "The negotiations on the six-party talks and all the actions the parties take will be judged on their own merits."
He added that President Bush and Rice would make decisions based on Washington's "compelling interest" to rid North Korea of its nuclear program.
The State Department and the Pentagon have said they are not involved in Thursday's congressional briefings. A White House spokeswoman declined to comment.
In the initial days after the attack on the Syrian facility, fewer than two dozen people in the U.S. government were briefed on the intelligence surrounding the strike, and all were ordered to keep the information secret, according to a Pentagon official who asked not to be named.
The briefing notice to House members describes Thursday afternoon's topic as regarding the Middle East, a congressional source said.
The briefing might include video shot inside the Syrian facility before it was bombed, although a final decision about whether to show the video has not been made. It is believed that the video was shot by Israeli intelligence or a mole for the Israelis, the source close to the administration said.
A media briefing is also being considered, but some in the administration and Israel are concerned about provoking Syria with the disclosure.
But when Defense Secretary Robert Gates was asked Wednesday when the American public would be told about allegations of North Korea's nuclear assistance to Syria, he replied: "Soon."
Israel bombed the facility September 6, 2007, and satellite images show that little was left of it.
Since the strike, questions have arisen as to why the Israelis took the action and whether the United States supported the mission.
Syrian officials said the bombing was an Israeli raid on a building they described as an empty military warehouse.
The International Atomic Energy Agency said in October that the agency had "no information about any undeclared nuclear facility in Syria and no information about ... reports" regarding an alleged facility.
A satellite photograph of the area taken in January seemed to indicate new construction on the site where the facility once stood. E-mail to a friend
CNN's Elise Labott, Deirdre Walsh, Pam Benson, Jamie McIntyre and Adam Levine contributed to this report