Seoul, South Korea ? An American destroyer tailed a North Korean ship Tuesday as it sailed along China’s coast, U.S. officials said, amid concerns the vessel is carrying illicit arms destined for Myanmar.

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.

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, U.S. defense and counterproliferation officials said Tuesday that an impending missile test threatened by North Korea is expected to launch short- to medium-range missiles rather than a long-range missile similar to one tested in April. The officials spoke on condition of anonymity to discuss sensitive intelligence.

Japanese media have reported that the North Koreans appear to be preparing for a long-range test planned sometime around July 4 and to be fired toward Hawaii.

The North Korean-flagged Kang Nam left the port of Nampo last Wednesday, with the U.S. destroyer following it. Two Pentagon officials described a relay operation in which the destroyer USS John S. McCain would hand over surveillance of the ship to the destroyer USS McCampbell. The officials spoke on condition of anonymity to discuss intelligence.

The North has said it would consider any interception “an act of war,” and an editorial Tuesday in its main Rodong Sinmun newspaper said the Korean peninsula was on the brink of a nuclear war.

“A grave situation is being forged in the Korean peninsula where a nuclear war could happen with any accidental factor due to the sanctions,” said the editorial carried on the government-run Uriminzokkiri Web site.

But an armed skirmish is unlikely, analysts say, though the North Korean crew may have rifles.

“A cargo ship can’t confront a warship,” said Baek Seung-joo of the Korea Institute for Defense Analyses.