Roh expressed optimism the August 27-29 talks in Beijing could lead to a breakthrough in the dragging stand-off, in a speech to mark South Korea's liberation from Japanese colonial rule 58 years ago.

"Luckily, we begin to see signs of a solution to the problem caused by the North's nuclear program," Roh said. "North Korea should not miss this opportunity."

The United States, Japan, China, Russia and the two Koreas have agreed to take part in the talks after weeks of wrangling over a dialogue format.

The South Korean leader said if North Korea dropped its nuclear ambitions, South Korea would help to rebuild the communist state's devastated economy.

"It must dismantle its nuclear program and open itself up successfully. Nuclear weapons can never become a shield to protect its system. On the contrary, the program will cause further isolation and crisis."

He renewed his call for a peaceful end to the stand-off and called for an early settlement.

"The North Korean nuclear issue should be resolved as early as possible. It has to be settled peacefully at all costs," he said.

The nuclear crisis erupted in October last year when the United States accused Pyongyang of reneging on a 1994 bilateral nuclear accord by setting up a clandestine program based on enriched uranium.

North Korea responded by kicking out UN nuclear inspectors and withdrew from the treaty. It has since claimed to have reprocessed 8,000 spent fuel rods at its nuclear plant at Yongbyon.

In the speech at the independence memorial hall in Cheonan, 90 kilometers (55 miles) south of Seoul, Roh called the 1910-45 Japanese colonial rule of Korea a "humiliating history" that Korea must not allow to be repeated.

He vowed to boost the country's self-defense capability, while stressing a need to gradually reduce Seoul's heavy security reliance on Washington.

"The country has emerged as the 12th largest economy in the world. It is about time we took responsibility for defending ourselves," he said.

But he said efforts to improve South Korea's ability to defend itself should not undermine the current South Korea-US military alliance.

WAR.WIRE