Sen. John McCain says the U.S. should board a North Korean ship it is tracking if hard evidence shows it is carrying missiles or other cargo in violation of U.N. resolutions.
McCain says that such cargo would contribute to the proliferation of weapons of mass destruction to nations that pose a direct threat to the United States.
South Korean media reported Sunday that the ship was sailing toward Myanmar via Singapore.
The Obama administration has said it's prepared to confront ships believed to be carrying contraband materials to North Korea, but would not try to forcibly board them.
McCain appeared Sunday on CBS' "Face the Nation."