SEOUL: A trio of top-level North Korean officials, including the man seen as leader Kim Jong-Un's number two, flew to South Korea Saturday for an extremely rare visit that will raise hopes of a breakthrough in cross-border ties.

The three senior leaders, making a surprise visit to attend the closing ceremony of the Asian Games in Incheon, arrived shortly after 10:00 am (0100 GMT), with TV footage showing them being escorted into black sedans at Incheon airport.

Officials said they would attend a luncheon with South Korea's top official for North Korean affairs, Unification Minister Ryoo Kihl-Jae, as well President Park Geun-Hye's top national security adviser.

The two Koreas have remained technically at war since the end of the 1950-53 Korean conflict, and the meeting with Ryoo would mark the highest level contact for years.

Unification Ministry spokesman Lim Byeong-Cheol identified the three leaders as newly-elected vice chairman of the National Defence Commission Hwang Pyong-So, Choe Ryong-Hae and Kim Yang-Gon.

The trip comes at a time when Kim Jong-Un has not been seen in public for a month, fuelling speculation about his health and even triggering unsubstantiated rumours of a coup.

The young leader did not attend a recent meeting of the North's rubber-stamp parliament at which Hwang Pyong-So — seen as second only to Kim in the leadership hierarchy — cemented his position by being appointed a vice-chairman of the powerful NDC, which Kim leads.

Hwang also holds the key post of head of the North Korean military's political department.

The Unification Ministry said the three would meet the North Korean team participating in the Asian Games and then attend the closing ceremony in the evening before flying back to Pyongyang.

Ministry spokesman Lim said Seoul hoped the presence of the three senior leaders would “provide momentum for a positive development in inter-Korean ties”.

'Unprecedented'

Recent South Korean requests for a resumption of high-level talks with the North have been rebuffed by Pyongyang, still smarting over a series of what it sees as provocative joint military exercises between South Korea and the United States.

The North recently conducted an extended series of rocket and missile firings into the Sea of Japan.

Kim Yang-Gon is head of the United Front Department of the ruling Workers' Party of Korea in charge of South Korea-related affairs.

Choe Ryong-Hae's inclusion in the leadership trio is most likely down to his position as head of the North's Sports Commission.

Choe was initially identified as Kim's number two following the execution last December of Kim's uncle and political mentor, Jang Song-Thaek.

But his star appears to have dimmed of late, while Hwang has moved swiftly up the power structure, replacing Choe as military political chief and NDC vice chairman.

Professor Yang Moo-Jin of the University of North Korean Studies in Seoul said he believed both men were still close aides of Kim Jong-Un.

“It is something quite unprecedented for North Korea to send two of the leaders' closest confidantes to the South,” Yang said, speculating that they might be carrying a letter from Kim.

“I think this is really about the North wanting to show to the world that it is leading efforts to improve ties with the South,” Yang said.

North Korea wants a resumption of six-party talks on its nuclear programme, but the United States and South Korea insist it must first make a tangible commitment to abandoning nuclear weapons.