South Korea's national security adviser Kim Kwan-Jin, left, shakes hands with Hwang Pyong-So , director of the North Korean military's General Political Bureau, the top military post in North Korea, during a luncheon meeting. (Korea Pool/AFP/Getty Images)

North and South Korea have agreed to hold another round of high-level talks after a top-level Northern delegation, including the men thought to be second and third in command behind Kim Jong Un, paid a surprise visit to the South on Saturday.

The unusual and unannounced trip — the first such high-level visit in more than five years — comes at a time of intense speculation about North Korea’s leadership, given that Kim, the third-generation leader of the communist state, has not been seen in public for a month.

It also comes amid a steady stream of disparaging comments from both sides, with South Korean President Park Geun-hye recently calling for the international community to help in “tearing down the world’s last remaining wall of division,” and the North calling Park an “eternal traitor” in response.

“It’s a big deal, it’s really a big deal, because it’s completely unprecedented,” said Andrei Lankov, a North Korea scholar who studied in Pyongyang and now teaches in Seoul.

The 11-strong group from North Korea was led by Hwang Pyong So, widely considered Kim’s deputy. He’s the top political official in the Korean People’s Army and vice chairman of the National Defense Commission, which is led by Kim.

Another member of the delegation was Choe Ryong Hae, who has performed both of the roles currently performed by Hwang and is chairman of the State Physical Culture and Sports Commission. That job was previously held by Jang Song Taek, the influential uncle that Kim Jong Un had executed last December, according to NK News, a Web site that monitors the North.

The third top official was Kim Yang Gon, secretary of the central committee of the Korean Workers’ Party and head of the United Front Department, the North’s equivalent of the South’s unification ministry.

The delegation had lunch with South Korea’s unification minister, Ryoo Kihl-jae, and Kim Kwan-jin, the national security adviser to Park. South Korean media showed photos of Ryoo shaking hands with Hwang, in North Korean military uniform bedecked with medals, and later sitting down for a meeting together.They also met South Korean Prime Minister Chung Hong-won, who later said he viewed the visit as a good omen. “I hope that it will lead to South-North cooperation and exchanges,” his office said he told the North Koreans, according to Yonhap News.

The two sides agreed to hold another round of talks, perhaps even before the end of this month, and in a sign of what counts as progress when it comes to diplomatic relations with North Korea, the delegation from Pyongyang agreed to call them “talks.”

“The delegates agreed to have working-level consultations on specific matters ahead of the high-level meeting,” a spokesman for the South’s unification ministry said in a statement after the meetings. “The North explained that it intends to continue inter-Korean dialogue by naming the upcoming meeting the second round of talks.”

However, the North Koreans did not meet Park, the South Korean president, with the spokesman saying a meeting “was not realized due to limited time.”

Still, the sudden visit, which analysts said appeared to take South Korea by surprise, sparked talk of a thaw on the divided peninsula. The delegation arrived Saturday morning, ostensibly to attend the closing ceremony of the Asian Games, which had been held in Incheon, the airport city about an hour west of Seoul.

“This group has way too much firepower for the closing ceremony of the Asian Games,” said John Delury, a North Korea watcher at Yonsei University in Seoul. “The games are a subterfuge for some kind of inter-Korean movement. I do think they’re coming with a substantive agenda for Park.”

This is the highest-level North Korean delegation to visit the South since 2009, when two top officials — including Kim Yang Gon, who visited again Saturday — visited to pay the North’s respects after the death of Kim Dae-jung, the president who championed rapprochement between the two Koreas.

Lankov said North Korea appeared to be enlarging its “charm offensive” as it tries to “get away from excessive Chinese influence.” North Korea’s foreign minister has been traveling the world, speaking to the United Nations General Assembly last month and now visiting Russia. Officials have been holding talks with the Japanese government over a decades-old abduction dispute.

Even as his top aides visited South Korea, Kim Jong Un remained mysteriously missing from the public eye. He has not been seen since Sept. 3, and his unusual absence from a session of the Supreme People’s Assembly in Pyongyang last month was followed by even more unusual reports in the state media that he was in an “indisposed condition.”

This triggered rumors covering every possibility from a stroke to a coup d’etat. A South Korean newspaper reported that the leader is merely recovering from surgery on both ankles, although, as with most reports about North Korea, this cannot be verified.

The visit of such a high-level delegation to South Korea on Saturday — combined with the flurry of other trips — added weight to the theory that Kim is simply ill, Delury said.

“This kind of travel would be way too out there if anything serious was going on in North Korea, so I don’t think it’s a sign of a coup,” he said. “But to what extent are they doing this because of all the speculation? We can’t rule out that this is part of a campaign to show that everything is normal there.”

If the Asian Games were just a pretense, it was one that the North Koreans were keeping up.

“As I watched some people [in the stands] shouting unification slogans and waving unification flags on TV, I’m proud that the sports sector is taking the initiative in terms of the national unification,” Choe said Saturday, according to reports from Seoul.

North Korea competed at the Asian Games, with its men’s soccer team playing South Korea in the final this week. The South won 1-0.

While both Koreas espouse unification for the peninsula, divided since the end of World War II, each has different ideas about what a reunited country should look like: The industrialized South thinks capitalism and democracy should prevail, while the communist, impoverished North maintains that its system is morally superior.