WASHINGTON » The U.S. military is tracking a ship from North Korea that could be carrying illicit weapons, the first vessel monitored under tougher new U.N. rules meant to rein in and punish the communist government following a nuclear test, officials said yesterday.

Defense Secretary Robert Gates said he has ordered additional protections for Hawaii just in case North Korea launches a long-range missile over the Pacific Ocean.

The suspect ship could become a test case for interception of North Koran ships at sea, something the North has said it would consider an act of war.

Officials said the United States is monitoring the voyage of the North Korean-flagged Kang Nam, which left port in North Korea on Wednesday. Yesterday it was traveling in the Pacific Ocean off the coast of China, two officials said on condition of anonymity to discuss intelligence.

The ship is among a group that is watched regularly but is the only one believed to have cargo that could potentially violate the U.N. resolution, one of the officials said.

Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, did not specifically confirm that the U.S. was monitoring the ship when he was asked about it at a Pentagon news conference yesterday.

“;We intend to vigorously enforce the United Nations Security Council Resolution 1874 to include options, to include, certainly, hail and query,”; Mullen said. “;If a vessel like this is queried and doesn't allow a permissive search,”; he noted, it can be directed into port.

Gates, speaking at the same news conference, said the Pentagon is concerned about the possibility of a North Korean missile launch “;in the direction of Hawaii.”;

A Japanese newspaper reported yesterday that North Korea might fire its most advanced ballistic missile toward Hawaii around the Fourth of July holiday.

The missile now being readied in the North is believed to be a Taepodong-2 with a range of up to 4,000 miles and would be launched from North Korea's Dongchang-ni site on the northwestern coast, the Yomiuri newspaper said.