North Korea may be cooperating with Syria on some sort of nuclear facility in Syria, according to new intelligence the United States has gathered over the past six months, sources said. The evidence, said to come primarily from Israel, includes dramatic satellite imagery that led some U.S. officials to believe that the facility could be used to produce material for nuclear weapons.

The new information, particularly images received in the past 30 days, has been restricted to a few senior officials under the instructions of national security adviser Stephen J. Hadley, leaving many in the intelligence community unaware of it or uncertain of its significance, said the sources, who spoke on the condition of anonymity. Some cautioned that initial reports of suspicious activity are frequently reevaluated over time and were skeptical that North Korea and Syria, which have cooperated on missile technology, would have a joint venture in the nuclear arena...

...In talks in Beijing in March 2003, a North Korean official pulled aside his American counterpart and threatened to "transfer" nuclear material to other countries. President Bush has said that passing North Korean nuclear technology to other parties would cross the line.

Israel conducted a mysterious raid last week against targets in Syria. The Israeli government has refused to divulge any details, but a former Israeli official said he had been told that it was an attack against a facility capable of making unconventional weapons.

Others have speculated that Israel was testing Syria's air defenses in preparation for a raid on Iran or that Israel was targeting weapons destined for Hezbollah in Lebanon...