SEOUL, Dec 4 (AFP) - The United States would deploy up to 690,000 troops on the Korean peninsula if a new war breaks, according to a South Korean defense ministry white paper published Monday.

The United States, which has 37,000 troops permanently in the South, remains concerned about North Korea's military strength despite the North-South reconciliation process launched this year.

US defense chiefs have considerably increased the number of troops that would be deployed in any new Korean conflict. The figure has risen from 480,000 in plans made in the early 1990s and 630,000 in the mid-1990s, the policy document said.

"The latest Time Phased Forces Deployment Data for any contingency on the Korean Peninsula is comprised of 690,000 soldiers, 160 navy ships and 1,600 planes," it said.

The United States fought with the South against the communist North in the 1950-53 Korean War and has kept troops in South Korea under a mutual defense pact to deter any new invasion attempt.

The war only ended in a truce and the de-militarized zone remains one of the world's most volatile conflict flashpoints. A summit in June between the South's President Kim Dae-Jung and the North's supreme leader Kim Jong-Il produced an accord to move toward reconciliaton. But it has done little to reduce military tensions, according to US and South Korean military chiefs.

"We always have various options," a US military official told AFP, refusing to give details on the deployment of extra troops and equipment planned by the Pentagon.

The South Korean defense ministry, however, described the increase as the result of a new US "win-win strategy," which would require the United States to have the capability to fight two wars simultaneously, such as in the Middle East and East Asia. The US military numbers a total of 1.37 million service men and women.

"This shows a strong US determination to guard the Korean peninsula despite its plan to reduce the entire number of troops," said the White Paper.

Along with equipment to counter weapons of mass destruction, the US plan focused on the deployment of aircraft carriers and advanced aircraft to attack enemy artillery units in the early stages of any war, it said. The white paper also called for a strong military partnership between the allies to deter war on the Korean peninsula.

"South Korea's partnership with the United States will ensure peace and deterrence of war on the peninsula and create an atmosphere for peaceful unification," it said.

"And with sights beyond unification, this partnership will contribute to the stability of Northeast Asia.

"Based upon a robust combined defense posture, (South Korea) and the United States continue close consultation in implementing a policy of reconciliation and cooperation toward the North." Until the June summit, North Korea had insisted on the withdrawl of US forces from South Korea.

President Kim has said he wants US troops to remain and said his North Korean counterpart agreed on the need for a US military presence on the peninsula.

This has led to speculation that US troops in South Korea could, after any eventual reunification, become a regional peacekeeping force.