North and South Korean leaders have agreed to meet next month at the truce village of Panmunjom, on the North-South line 40 miles north of Seoul, for the third inter-Korean summit, a top South Korean official has announced.

The sudden announcement of talks between North Korea’s leader Kim Jong-un and South Korea’s President Moon Jae-in marks a dramatic potential step towards inter-Korean harmony – and a dividend of moves towards peace initiated at last month’s Winter Olympics in the South Korean mountain district of Pyeongchang.

Chung Eui-yong, Mr Moon’s national security adviser, announced the summit at a briefing at which he had been expected only to report on his visit to Pyongyang on Monday, when he and other members of his delegation were hosted to dinner by Mr Kim.

Mr Kim was said to have described that conversation as “open-hearted”, but there was no hint that the two sides would agree right away to a summit. He had invited Mr Moon to the summit three weeks ago in a letter that his younger sister, Kim Yo-jong, personally delivered after attending the PyeongChang opening ceremonies.

Mr Moon at the time said agreeing to a summit depended on “the right conditions”. Clearly Mr Kim came through with acceptable responses.

On the streets of Seoul, Koreans responded with feelings ranging from exhilaration to scepticism. “This is great,” said Kim Han-jin, a young businessman. “We should keep talking until the North is denuclearised.” Another person, who did not want her name used, said: “The US should cooperate instead of making threats against North Korea.” Korean conservatives, however, took quite a different view. “President Moon is falling for Kim Jong-un’s double talk,” said a middle-aged man. “He won’t give up anything. He wants to weaken our defences.”

First and foremost, said Mr Chung, Mr Kim agreed “the denuclearisation issue may be discussed as an agenda for the North-US dialogue” – an understanding that marked a clear departure from North Korea’s previous refusal to discuss the nuclear issue at all.

Indeed, said Mr Chung, Mr Kim “has clearly stated that the denuclearisation of the Korean Peninsula was an instruction of his predecessor” – that is, his father, Kim Jong-il. Mr Kim, said Mr Chung, said “there has been no change to such an instruction”.

Mr Kim reportedly fortified that promise with assurances that American leaders are likely to greet with scepticism. Analysts quickly noted that Mr Kim hoped, by agreeing to holding a summit so soon, to throw off planning for joint US-Korean military exercises set to begin early next month.

Both Mr Moon and President Donald Trump have insisted the war games will be held as scheduled, but South Koreans are sure to express doubts as to whether they are such a good idea in the run-up to what would be the third inter-Korean summit – the first since the late Roh Moo-hyun met Kim Jong-il in Pyongyang in 2007. Roh’s predecessor, the late Kim Dae-jung, flew to Pyongyang in June 2000 for the first inter-Korean summit – a dividend of Mr Kim’s “sunshine policy” of North-South reconciliation.

This summit would be fundamentally different from the other two in one aspect. The agreement to meet at Panmunjom, where the Korean War armistice was signed in 1953, means that Mr Moon would not be in the position of going as a supplicant to Pyongyang. Rather, the two would be meeting on equal, neutral ground – symbolic of their mutual desire to keep up the momentum generated by the Olympics.

“The North side,” said Mr Chung at his briefing at the Blue House, the presidential residence and office complex, “clearly affirmed its commitment to the denuclearisation of the Korean Peninsula and said it would have no reason to possess nuclear weapons should the safety of its regime be guaranteed and military threats against North Korea removed.” Indeed, he added, “the North promised not to use not only nuclear weapons but also conventional weapons against the South”.

North Korea Military Parade Show all 6 1 /6 North Korea Military Parade North Korea Military Parade In this image made from video released by KRT on Feb. 8, 2018, a military parade is held at Kim Il Sung Square in Pyongyang, Thursday, Feb. 8 2018, just one day before South Korea holds the opening ceremony for the Pyeongchang Winter Olympics. (KRT via AP Photo) AP North Korea Military Parade This screen grab taken from North Korea's KCTV on February 8, 2018 shows members of North Korea's military taking part in a parade, with missiles being displayed, in Kim Il Sung Square in Pyongyang. North Korea staged a military parade in Pyongyang on February 8 to mark the 70th anniversary of its armed forces, in a show of strength just a day before the Pyeongchang 2018 Winter Olympic Games open in the South. / AFP PHOTO / KCTV / KCTV / -----EDITORS NOTE --- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / KCTV" - NO MARKETING - NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - NO ARCHIVESKCTV/AFP/Getty Images AFP/Getty Images North Korea Military Parade In this image made from video released by KRT, North Korean soldiers march during a military parade in Pyongyang, Thursday, Feb. 8 2018. North Korea held a military parade and rally on Kim Il Sung Square on Thursday, just one day before South Korea holds the opening ceremony for the Pyeongchang Winter Olympics. (KRT via AP Photo) AP North Korea Military Parade In this image made from video released by KRT on Feb. 8, 2018, North Korean leader Kim Jong Un, right, inspects honor guards, along with his wife Ri Sol Ju, center, during a military parade in Pyongyang, Thursday, Feb. 8 2018. North Korea held a military parade and rally on Kim Il Sung Square on Thursday, just one day before South Korea holds the opening ceremony for the Pyeongchang Winter Olympics. (KRT via AP Photo) AP North Korea Military Parade In this image made from video released by KRT on Feb. 8, 2018, North Korean leader Kim Jong Un, center, watches the military parade in Pyongyang, Thursday, Feb. 8 2018. North Korea held a military parade and rally on Kim Il Sung Square on Thursday, just one day before South Korea holds the opening ceremony for the Pyeongchang Winter Olympics. (KRT via AP Photo) AP North Korea Military Parade This screen grab taken from North Korea's KCTV on February 8, 2018 shows North Korean leader Kim Jong Un speaking during a military parade in Kim Il Sung Square in Pyongyang. North Korea staged a military parade in Pyongyang on February 8 to mark the 70th anniversary of its armed forces, in a show of strength just a day before the Pyeongchang 2018 Winter Olympic Games open in the South. / AFP PHOTO / KCTV / KCTV / -----EDITORS NOTE --- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / KCTV" - NO MARKETING - NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - NO ARCHIVESKCTV/AFP/Getty Images AFP/Getty Images

This policy, if followed, marks a sharp reversal from the pattern of missile and nuclear tests that have characterised Kim Jong-un’s rule. Mr Kim has ordered 10 missile tests, including three of long-range ballistic missiles theoretically capable of delivering a warhead to American targets, since Mr Moon won the presidency in a “snap election” last May after the impeachment, ouster and jailing of his conservative predecessor, Park Geun-hye. Mr Kim has also ordered two underground nuclear tests.

Even if South and North Korea do stage possibly modified military exercises in the next few weeks, the plan for the summit is certain to force Mr Trump to abandon any thought of exercising the “military option”, possibly a preemptive strike on the North’s nuclear and missile facilities. Mr Moon, while calling for strengthening of the South’s armed forces along with denuclearisation, has opposed any attack on North Korea as almost certain to invite a counter-attack on South Korea’s densely populated capital region of Seoul and the nearby west coast port Incheon.