Fallon suggested in a session with defense reporters here that the shifting balance of power on the Korean peninsula might allow for a further reduction of the US military presence on the ground in South Korea.

The upbeat assessment comes despite continuing US concerns about Pyongyang's nuclear and missile programs, which Fallon said were "disconcerting."

But, he said, the test failure July 5 of a North Korean long-range Taepodong-2 missile shows it will be "a while" before that threat fully materializes.

"The fact that it failed, the fact that apparently the last time they did this a few years ago was also a failure, indicates some problems there," he said.

"They've got work to do. And it seems to me before we can credibly give them capability, or signs of building, they have to demonstrate they can actually get a missile off the pad, and have it fly," he said.

Fallon said North Korea has lost ground militarily both because of the growing strength of the South Korean military and the impact of sanctions and years of widespread starvation in the north.

"As I look at their people, just the physical appearance of them, they appear year by year to be physically diminished," he said. "People are starving, there is not enough food, and so there's a physical problem."

"Also there is also a major financial problem. We've been choking them financially from the outside," he said.

Fallon said the North Korean military has some strengths such as it special warfare capabilities.

"So I'm not going to discount this threat, but the ability for them to sustain major combat for a lengthy period of time I believe is much less than it was in the past, particularly given this growth in South Korean capability," he said.

"Not only do they have well fed, well trained, well organized troops in the south, but they have had increasing exposure to new technology from us and other sources," he said.

"North Korea would be very hard pressed to be successful for any period of time in an attack in the south," he said.

Moreover, he said, South Korea is moving closer to the north because it wants a reunified peninsula.

The US military for its part has been transferring key missions to the South Koreans, strengthening their ability to defend against an invasion by the north, he said.

"My assessment is that the ROK (Republic of Korea) military is very capable of defending themselves now, particularly their ground forces," Fallon said.

"They would clearly benefit from our assistance and engagement, particularly in air and naval. But their ground forces I think are very capable of defending South Korea," he said.

Under agreements dating from the 1950-53 Korean War, a US general commands a combined US-South Korea force in wartime. But South Korea is pressing to take over full wartime operational control of forces in its territory.

"Assuming that this topic is agreed for execution in some manner, then we'll have to go back and look at all those forces, and reassess that," he said.

Current plans call for a reduction of US forces in South Korea to 25,000 by 2008 from 32,500 today.

That will leave a US combat brigade and a "fair number" of US military personnel who are there to provide the staff structure for US troops flowing into the country in the event of an invasion, he said.

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