The White House claims the evidence, including a video taken at the facility, supports allegations that North Korea helped the country build a plutonium-based nuclear site.
The video shows North Koreans among the workers inside the facility and shows a reactor core with a similar design as that of the North Korean reactor at Yongbyon, reported the Washington Post and the New York Times.
After being briefed on the classified information, a top member of the House intelligence committee told the Associated Press that the Syrian site threatened to spread nuclear weapons technology.
“This is a serious proliferation issue, both for the Middle East and the countries that may be involved in Asia,” said Rep. Pete Hoekstra, R-Mich.
Israel showed the video to U.S. officials before bombing the site on Sept. 6, 2007, because Bush administration officials had expressed skepticism that the facility was a nuclear reactor built with North Korea’s assistance, the Post reported.
The White House had previously refused to discuss the reason for the air strike, even after the Times published an article in October revealing that the target was believed to be a nuclear site under construction.
Officials later told the paper they feared Syria would retaliate against Israel if the information was released.
The evidence members of Congress will be shown also includes pre-attack images taken inside the reactor building. It is believed that the video was shot by Israeli intelligence or a mole working at the facility, reported CNN.
White House press secretary Dana Perino said the Bush administration would issue a public statement later in the day.
Intelligence officials who have seen the evidence consider it “extremely compelling,” a U.S. official told the AP, adding that it was gathered from a variety of sources, not just Israeli intelligence. The official spoke to the news agency on condition of anonymity.
On Wednesday, Syrian Ambassador Imad Moustapha denied the video was valid.
“If they show a video, remember that the U.S. went to the U.N. Security Council and displayed evidence and images about weapons of mass destruction in Iraq. I hope the American people will not be as gullible this time around,” he told the Washington Post.
Syrian officials have said the bombed building was an empty military warehouse. They have refused to let nuclear inspectors visit the location, which was bulldozed after the bombing.
Syria’s ambassador to Britain, Sami al-Khiyami, told Reuters Thursday, “This has nothing to do with North Korea and Syria. They just want to exert more pressure on North Korea. This is why they are coming up with this story.”
Syria did not declare the reactor to the International Atomic Energy Agency, putting the country in possible violation of the international nuclear nonproliferation treaty.
The reactor was not yet complete, but already resembled the North Korean reactor, an anonymous U.S. official told the AP.
The release of the video could complicate U.S. relations with North Korea. During six-party talks with the country about ending its nuclear program, U.S. diplomats have pressured North Korea to admit to cooperating with Syria, but to no avail, reported the AP.
Under an agreement reached last year with the United States, China, Japan, South Korea and Russia, the North is required to give a full account of its nuclear programs, including whether it has shared nuclear technology.
North Korea claims it gave the nuclear declaration to the U.S. in November, but U.S. officials say the North never produced a “complete and correct” declaration.