"I'm confident the North Korean nuclear issue will rapidly arrive at a complete resolution," South Korean President Roh Moo-hyun said, citing a detailed multilateral agreement aimed at the North's denuclearization that was approved by the leaders of the two Koreas.
Roh's speech was read in the National Assembly by Prime Minister Han Duck-soo.
The president traveled to Pyongyang last week for talks with Kim Jong Il for the first inter-Korean summit in seven years.
The leaders signed an accord pledging to make "joint efforts to ensure the smooth implementation" of agreements made at a new round of six-nation talks involving the two Koreas, the U.S., China, Russia and Japan.
In those talks, held at the end of September in Beijing, North Korea agreed to disable its main nuclear facilities and declare all its programs by the end of this year.
At the three-day meeting the leaders also agreed to cooperate in ending military hostility - highlighted by efforts to replace a Korean War-ending armistice with a peace treaty - and boost cross-border economic projects.
"Inter-Korean relations have entered a new phase," Roh said in the speech to lawmakers.
Separately, a team of U.S. nuclear experts, led by the State Department's top Korea expert, Sung Kim, prepared to depart for the North on Tuesday to create a plan for future teams to begin disabling the North's Yongbyon nuclear reactor.
The team, which includes technical experts from various U.S. government departments, will put in place a plan for its disablement, State Department spokesman Sean McCormack said earlier.
Other teams would then go to North Korea to disable it, he said.
A U.S. team of nuclear experts led by Sung Kim surveyed the North's main nuclear facilities last month.
The Yongbyon nuclear complex is believed to have produced enough plutonium for perhaps more than a dozen bombs - including the device North Korea detonated a year ago to prove its long-suspected nuclear capability.
South Korea's Yonhap news agency reported Sunday, without citing sources, that the North will likely start disabling its nuclear facilities in mid-October and that the process would take about 45 days.
The North is also likely to agree to removing core parts from its nuclear facilities and placing them under the oversight of the International Atomic Energy Agency to meet the deadline, Yonhap also said.