South Korea sent special envoys to the United States and other countries Friday to brief them on the accord at this week's summit with North Korea that calls for multinational talks to formally end the Korean War. South Korean President Roh Moo-hyun and North Korean leader Kim Jong Il agreed Thursday to pursue a peace treaty to replace the current armistice that ended the 1950-53 Korean War, and to seek a meeting of parties to the cease-fire to discuss the matter. Establishing a peace treaty would require the participation of the US and China, which also fought in the conflict. "Before us lies the task of establishing a peace regime on the Korean peninsula, which our people yearn for," Unification Minister Lee Jae-joung told reporters Friday. "In this regard, special government envoys were dispatched to the United States, Japan, China and Russia." US President George W. Bush told Roh last month that he was willing to formally end the war, but insisted it could only happen after Pyongyang's total nuclear disarmament. State Department spokesman Sean McCormack stressed Thursday that the peace issue is tied to the nuclear issue. "I think the South Korean government talked about in the context of arriving at a peace agreement on the Korean peninsula the need to move forward on the six-party talks as a whole," he said of international arms talks aimed at ridding the North of nuclear weapons and programs. Thursday's agreement cited the nuclear issue in a single sentence, saying the North and South would make "joint efforts to ensure the smooth implementation" of previous accords from the six-nation talks "for the solution of the nuclear issue on the Korean peninsula." Pyongyang shut down its sole operating reactor at Yongbyon in July after the US reversed its hard-line policy against the regime, the first concrete progress from years of talks that also have included China, Japan, Russia and South Korea. Earlier this week, North Korea committed to going further than ever before to scale back its nuclear ambitions by pledging at arms talks with the US and other regional powers to disable its main nuclear facilities and declare all its programs by the end of the year. In return, the US offered to "begin the process" of eventually removing Pyongyang from its blacklist of countries sponsoring terrorism and lift other sanctions. On Friday, however, the North's official news agency claimed the US firmly promised to do so. The inter-Korean summit accord also calls for an expansion of economic cooperation, including establishing a new special economic zone on North Korea's west coast. They also agreed to accelerate the development of an existing joint industrial park in the North Korean border city of Kaesong and start a regular cargo rail service there. Roh instructed the Cabinet on Friday to draw up specific plans on implementing the accord, his spokesman Cheon Ho-seon said. Cheon also said Roh raised the sensitive issue of former South Korean soldiers and civilians believed to be held in North Korea during this week's summit, but could not reach agreement with Kim because their positions were far apart. "President Roh raised the issues of POWs and abductees ... but failed to bring an outcome due to big differences in perceptions," Cheon said without elaborating. South Korean Defense Minister Kim Jang-soo also said he raised the POW issue while talking to North Korean Defense Minister Kim Il Chol and demanded the North return hundreds of South Korean POWs, but received no response. According to South Korean government statistics, some 545 soldiers captured during the 1950-53 Korean War are believed still alive in the North, along with 480 abductees taken by the communist nation _ mostly fishermen whose boats have strayed across the border since the war's end. The North claims there are no prisoners or abductees in the country, insisting people there have gone voluntarily. The South's defense minister also said that Roh proposed ways of "peacefully using" the 4-kilometer-wide Demilitarized Zone separating the two Koreas during talks with Kim Jong Il, but the North's leader rejected the offer, saying it's "too early" to do so.