WASHINGTON – The White House said Thursday that North Korea’s secret work on a nuclear reactor with Syria was “a dangerous and potentially destabilizing development for the world,” raising doubts about Pyongyang’s intention to carry through with a promised disclosure of its nuclear activities.

Seven months after Israel bombed the reactor, the White House broke its silence and said North Korea assisted Syria’s secret nuclear program and that the destroyed facility was not intended for “peaceful purposes.”

The disclosure could undermine six-party negotiations to try to resolve the nuclear standoff with North Korea. The White House issued a two-page statement after lawmakers were given details about the reactor in a series of briefings on Capitol Hill. The White House said the International Atomic Energy Agency also was being briefed on the intelligence.

While calling North Korea’s nuclear assistance to Syria a “dangerous manifestation” of Pyongyang’s nuclear weapons program and its proliferation activities, the U.S. said it remained committed to the talks.

The administration said that after the reactor was damaged beyond repair, Syria tried to bury evidence of its existence.

“This cover-up only served to reinforce our confidence that this reactor was not intended for peaceful activities,” White House press secretary Dana Perino said. “The Syrian regime must come clean before the world regarding its illicit nuclear activities.”

The Syrian nuclear reactor destroyed by Israeli jets was within weeks or months of being functional, a top U.S. official told The Associated Press, speaking on condition of anonymity because of the sensitivity of the matter. The official said the facility was mostly completed but still needed significant testing before it could be declared operational.

No uranium, which is needed to fuel a reactor, was evident at the site, a remote area of eastern Syria along the Euphrates River. But the U.S. official said the reactor was similar in design to a North Korean reactor at Yongbyon, which has in the past produced small amounts of plutonium, the marterial needed to make powerful nuclear weapons.

Top members of the House Intelligence Committee said the reactor posed a serious threat of spreading dangerous nuclear materials.

“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.

The White House also stressed that North Korea’s assistance on the Syrian reactor was an issue of “great international concern.”

“The construction of this reactor was a dangerous and potentially destabilizing development for the region and the world,” Perino said in the statement. “This is particularly true because it was done covertly and in violation of the very procedures designed to reassure the world of the peaceful intent of nuclear activities.

“The United States calls upon the international community to redouble our common efforts to ending these activities and preventing the spread of weapons of mass destruction in this critical region.”