WASHINGTON, June 27: The United States said Wednesday North Korea had launched ballistic missiles, adding it was “deeply troubled” by the move just as diplomatic powers negotiate to dismantle the Stalinist state's nuclear drive.

“The United States is deeply troubled that North Korea has decided to launch these missiles during a delicate time in the six-party talks,” National Security Council spokesman Gordon Johndroe said in a statement.

The statement did not reveal how many missiles were involved but Johndroe said the launches were “a violation of UN Security Council Resolution 1718, which prohibits North Korea from engaging in all ballistic missile activities.” Johndroe said the US government expects “North Korea to refrain from conducting further provocative ballistic missile launches,” which he said destabilize the security of northeast Asia.

North Korea should instead “turn its focus to implementing its commitments under the February 13th agreement, including the immediate shutdown of Yongbyon,” he added, referring to North Korea's main nuclear reactor site.

Under the February agreement, brokered with the United States, China, Japan, Russia and South Korea, UN inspectors were preparing on Wednesday to visit the Yongbyon reactor for their first on-site inspection in nearly five years.

The last time UN inspectors were in North Korea was in 2002, but they were kicked out in December that year at the start of a crisis that led to the regime's first-ever nuclear weapons test last year.

Under the February accord, the North has now promised to shut down and seal the Yongbyon facility under UN supervision in return for badly-needed energy aid and diplomatic concessions.

North Korea appeared to have test-fired a short-range missile into the Sea of Japan on Wednesday as part of a routine military exercise, South Korean news agency Yonhap reported.

A South Korean government source told Yonhap that North Korea appeared to have fired a missile with a range of some 100 kilometres at 11:30 am (0230 GMT).

“We have secured information on the launch of a short-range missile off the east coast in North Korea's South Hangyong province... The launch was probably seen as part of North Korea's routine exercise,” the source said.

The launch from a base near the northeastern port of Hamhung was believed to be of a ground-to-ground missile, Yonhap said. It was North Korea's third missile launch this year, the news agency said.

South Korean officials have played down the significance of North Korean missile launches this year, calling them part of normal military exercises. But the launches have heightened tensions in the region in the past decade.

In 1998 North Korea sparked alarm in Japan by test-firing a long-range missile over that country.

In July last year it test-fired seven missiles, including the Taepodong-2, which in theory could reach the US west coast. Those launches brought UN condemnation and missile-related sanctions.

Some analysts in Seoul say the North, after staging its first nuclear test last October, might be preparing the ground for another long-range missile test.

—AFP