President Lee Myung-bak said wealthy South Korea and its diplomatic partners had extended the offer of a "grand bargain" of economic assistance to the impoverished North once it gives up its nuclear ambitions.
"North Korea must not throw way what may be their last chance," he told the Council on Foreign Relations in New York. Returning to disarmament talks was the only way for North Korea to revive its economy and escape deep international isolation, Lee said.
Lee attends the U.N. General Assembly in New York this week and one item on the agenda is North Korea's nuclear weapons program.
Regional powers have been trying to get the North back to six-way talks on ending its nuclear weapons program in return for aid and diplomatic rewards, but Pyongyang has refused to return to the table and instead sought direct negotiations with Washington.
"Unfortunately, we do not find any signs anywhere that North Korea has such intentions," Lee said of the North's refusal to return to diplomatic talks with China, Japan, Russia, South Korea and the United States.
The six-party framework under which North Korea would get economic help and diplomatic recognition in exchange for nuclear disarmament was neither "threat to their regime nor an attempt to isolate them," he said.
