An American destroyer was tailing a North Korean ship suspected of transporting weapons as anticipation mounted today that the North could soon test-fire short- or medium-range missiles off its eastern coast.

It had earlier been reported that the North would test a a long-range missile similar to one tested in April. Japanese media said that could happen around July 4 and the missile would be fired toward Hawaii.

But U.S. defense and counterproliferation officials speaking on condition of anonymity said yesterday that it was expected the North would launch short- to medium-range missiles instead.

The Kang Nam left the port of North Korean port of Nampo a week ago, and the destroyer USS John S. McCain is following as it sails off the Chinese coast. The sailing sets up the first test of a new U.N. Security Council resolution that authorizes member states to inspect North Korean vessels suspected of carrying banned weapons or materials.

The sanctions are punishment for an underground nuclear test the North carried out last month in defiance of past resolutions. It's not clear exactly what the Kang Nam has on board, but it has transported illicit goods in the past.

The North has said it would consider any interception “;an act of war,”; with its main Rodong Sinmun newspaper warning yesterday the Korean peninsula was on the brink of a nuclear war.

A U.S. official said last week that the American destroyer has no orders to intercept the ship, but experts say the vessel will need to stop to refuel soon. The resolution prohibits member states from providing such services to ships accused of bearing banned goods.

Nearby Singapore—the world's largest refueling hub—says it will “;act appropriately”; if the ship docks at its port with suspicious goods on board.

Meanwhile, North Korea has issued a notice banning ships from the waters off its east coast from tomorrow through July 10 citing maritime firing drills, according to Japan's Coast Guard.

South Korea's Yonhap news agency reported today the North may fire a Scud missile with a range of up to 310 miles or a short-range ground-to-ship missile with a range of 100 miles during the no-sail period.