A North Korean ship shadowed by U.S. warships for the past two weeks on suspicion it is carrying illicit weapons has reversed course and may be returning to North Korea.

U.S. vessels have been monitoring the Kang Nam since it left a North Korean port 17 June. The ship's suspected destination was Burma or Singapore. News reports from the region say the ship is now in the waters off Vietnam and may be headed back to North Korea.

The Kang Nam is the first ship monitored under new U.N. Security Council sanctions that ban North Korea from selling arms and nuclear-related material.The sanctions were approved after North Korea's 25 May nuclear test, its second since 2006. U.N. resolution 1874 allows member nations to request permission to board and search any ship going to and from North Korea, suspected of carrying banned goods.

"I think there is every indication that there is some impact now of that resolution both on North Korea itself and, one of the stories is, also on Myanmar, or Burma," said John McKay, Research Director for Australia's APEC Studies Center at Monash University in Melbourne and a consultant for Analysis International.

"There is some indication that Myanmar already had already told the North Koreans that they would not allow the ship to dock, which shows that the resolution is having some effect," McKay said. ?I think this is an important development, but I think we?d be foolish to think this is somehow the way the problem [of North Korean weapons proliferation] was going to be solved once and for all."

The United States Tuesday announced it is targeting two firms for allegedly aiding North Korea's nuclear weapons program and missile proliferation. Iran-based Hong Kong Electronics allegedly helped two North Korean firms transfer millions of dollars of proliferation-related funds. Washington is also sanctioning Pyongyang-based Namchongang Trading Corporation for purchasing equipment suitable for uranium enrichment. The sanctions freeze any U.S. assets the two companies may have, and ban Americans from doing business with them.