"The Defense Agency has strong concern about such moves," Defense Agency Vice Minister Takemasa Moriya said Thursday following a report from South Korea about the deployment of the new intermediate-range missiles.

"We can assume that the range of North Korea's ballistic missiles will be extended further," Moriya told a news conference.

South Korea's defence ministry said in a report Wednesday that the North had been deploying new medium-range missiles, adding: "It is continuing its efforts to develop missiles, testing missile engines."

North Korea is believed to have 600 Scud missiles with ranges of between 300 kilometers and 500 kilometers (187 and 312 miles) and 100 Rodong-I missiles with a range of 1,300 kilometers.

US intelligence reports said the North had developed ballistic missiles with a range of up to 4,000 kilometers.

In August 1998 North Korea fired a suspected Taepodong ballistic missile over Japan and into the Pacific, a move which sent shockwaves around the region.

The South Korean report also said Pyongyang had beefed up its combat readiness since the US-led invasion of Iraq, fortifying military facilities and developing weapons of mass destruction at a five-megawatt nuclear reactor in Yongbyon.

North Korea and the United States have been trying to break the impasse over Pyongyang's nuclear program at six-party talks which include Japan, South Korea, China and Russia.

At six-party talks in Beijing last month, the United States gave Pyongyang three months to shut down and seal its nuclear weapons facilities in return for economic and diplomatic rewards.

WAR.WIRE