The chief of U.S. Naval operations said Saturday that a United Nations resolution was responsible changing the course of a North Korean ship suspected of carrying illicit weapons.

The Kang Nam 1, originally believed to be bound for Myanmar, has been shadowed for more than a week by the U.S. Navy. The North Korean freighter was the first vessel monitored under U.N. sanctions aimed at punishing the regime for conducting an underground nuclear test in May.

Adm. Gary Roughead said the ship was being closely watched and was now in the East China Sea.

Roughead said the ship's turnaround underlined the success of the U.N. resolution.

"I believe we are seeing the effects of the U.N. Security Council resolution," Roughead told reporters during a trip for meetings with Japanese military officials and American sailors here.

"I do believe the actions and the support that have been given to the Security Council resolution are making it very difficult for that ship," he said.

The resolution sought to clamp down on the country's trading of banned arms and material related to weapons by requiring U.N. member states to request inspection of ships suspected of carrying prohibited cargo.

North Korea has said it would consider any interception of its ships a declaration of war.

South Korean news channel YTN reported Friday, citing an unidentified diplomatic official, that Myanmar asked the Kang Nam to turn around.

The North, meanwhile, fired two missiles off its eastern coast Saturday, a South Korean official said.

Several short-range missiles that appeared to be Scuds were launched, a Yonhap news agency report said. North Korea fired four short-range missiles off the east coast on Thursday.

Roughead said the U.S. military was ready for North Korean missile launches.