Kim Dae-Jung defended his policy "sunshine" policy of reconciliation with his country’s neighbours, noting there had been no panic in the South after the Stalinist regime announced its first atomic weapons test.
Since the first stand-off over North Korea's nuclear programmes in the early 1990s, South Korea had been persistent in calling for a give-and-take package deal which the previous US administration under Bill Clinton agreed to, Kim said.
"Consequently, we were quite close to a success but the Bush administration came in and rejected the deal, only resulting in today's failure," he said during a speech in the southwestern city of Gwangju.
"The nuclear test by the North proved that the US policy towards the North had been ill-conceived. Now, the United States must not aim at regime change there but engage in a give-and-take deal with the North."
In the face of a nuclear-armed North Korea, Kim has said, the US may now consider military action but does not have enough capacity to do so since South Korea strongly opposes any attack.
"Secondly, the United States may not recognise the North as a nuclear-armed country and continue with pressure and economic sanctions against it. But this would only prod North Korea into further provocative acts," he added.
"The most desirable way is to resolve the issue through dialogue between the North and the United States. The United States must readjust its North Korea policy quickly by appointing a policy co-ordinator in the US Congress."
Kim's political rival and predecessor, Kim Young-Sam, on Tuesday called for a public apology both from his successor and the current president Roh Moo-Hyun, saying the sunshine policy was responsible for the North acquiring nuclear weapons.
But Kim Dae-Jung insisted the policy was successful in easing tensions on the Korean peninsula, although it had stumbled over bitter relations between the North and the US.
"[But for the sunshine policy], the nuclear test would have caused a great panic here and the people would have fallen over each other to flee from this country. But the situation here is very stabilised," he said.