http://www.navytimes.com/news/2009/06/navy_nkorea_061809w/

The military's top officer would not confim media reports on Thursday that the Navy was tracking a North Korean cargo ship suspected of carrying illegal weapons, equipment or nuclear fissile material that North Korea has been prohibited from transporting by the U.N. Security Council.

However, Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, did tell reporters at the Pentagon that “clearly, we intend to vigorously enforce the U.N. Security Council Resolution 1874,” although the Navy cannot use force to stop or board the vessel suspected of carrying the contraband.

A U.S. warship could hail the North Korean ship and ask to search it, and if the ship’s crew didn’t comply, the U.S. sailors could order the vessel to sail to the nearest port and request officials in that port to do the search — although the U.S. ship couldn’t use force for that, either.

“The resolution does not include an option for an opposed boarding or a noncompliant boarding,” Mullen said. “If we get to that point with a vessel we suspect has material which is unauthorized — that’s a report that goes back to the U.N.”

The U.N. Security Council voted to place additional strictures on North Korea after the country detonated a nuclear bomb May 25 and launched ballistic missiles into the ocean off Southeast Asia. One of the restrictions was that North Korean ships suspected of carrying nuclear material would be interdicted at sea, but the North has said it would consider the boarding of any of its ships as an act of war.