Former Prime Minister Goh Kun says the government should link inter-Korean economic cooperation to the nuclear issue if North Korea continues to boycott the six-party talks.

At a forum of international political leaders sponsored by Harvard University, Goh said the North's abrupt declaration on February 10 that it has nuclear weapons has provided an important turning point in addressing the issue.

North Korea says it will continue to boycott the six-party talks unless the United States gives up its hostile policy towards the North.

Goh warned that South Korea cannot co-exist with a nuclear-armed North, and that nuclear weapons development will drive the communist state into its worst-ever isolation and further aggravate its economy.