Kim Yong-nam will technically be the most senior official from the North ever to travel to the other side of the demilitarised zone that has for decades divided the two Koreas.
North Korea's ceremonial head of state will visit the South this week and attend the Winter Olympics opening ceremony as the divided peninsula witnesses a rare thaw after a year of high tensions over Pyongyang's nuclear programme.
Kim Yong-nam will technically be the most senior official from the North ever to travel to the other side of the Korean Demilitarised Zone that has for decades divided the two Koreas.
His trip will be the diplomatic high point of the rapprochement between the two Koreas triggered by the Pyeongchang Olympics in the South, which have their opening ceremony on Friday.
However, analysts warn that their newly warmed relations may not last long beyond the Games.
Tensions spiralled last year as the North carried out multiple weapons tests, including intercontinental ballistic missiles it says are capable of reaching the mainland United States, and its most powerful nuclear blast to date.
For months Pyongyang ignored Seoul's entreaties to take part in a "peace Olympics", until leader Kim Jong-un indicated his willingness to do so in his New Year speech.
That set off a rapid series of meetings which saw the two agree to march together at the opening ceremony and form a unified women's ice hockey team, their first for 27 years.
The North's Olympic participation would include a visit by a high-level delegation, they agreed.
It will be led by Kim Yong-nam, who is leader of the Presidium of the Supreme People's Assembly, the North's ruling party-controlled parliament, Seoul's unification ministry said in a statement late Sunday.
Kim - who is not a close blood relative of leader Kim Jong-Un - will arrive on Friday for a three-day visit, accompanied by three other officials and 18 support staff, the ministry added it had been told by Pyongyang.
The North's state-run news agency KCNA said the group would "soon visit south Korea to attend the opening ceremony of the 23rd Winter Olympics".
US Vice President Mike Pence will also be present at the same event.
As the nominal head of state, Kim Yong-nam will technically be the highest-level Northern official ever to visit the South, but he is largely considered a figurehead whose public diplomatic role leaves it unclear how much political power he really has.
He previously led the North's delegations to the 2008 Beijing Olympics and 2014 Sochi Winter Olympics, but does not hold the title of national president - and nor does leader Kim Jong-un.
Instead it is retained by Kim Jong-un's grandfather, the North's founder Kim Il-Sung, who remains Eternal President of the Democratic People's Republic of Korea - the country's official name - despite dying in 1994.
Speculation about who could lead the delegation had been rife in the South for weeks, with some analysts pointing to Choe Ryong-Hae, who is the vice chairman of the Central Committee of the ruling Workers' Party and seen as Kim Jong-un's right-hand man.
Others had even suggested the leader's younger sister Kim Yo-jong, who was recently promoted to a senior political position.
Choe was one of three senior Pyongyang officials who made a surprise visit to the South during the 2014 Asian Games along with former military chief Hwang Pyong-so and Kim Yang-gon, a top official on inter-Korea affairs who died in a car crash in 2015.
They did not go to the presidential Blue House in Seoul or meet then-South Korean President Park Geun-hye, and only met with Park's national security advisor and the then unification minister, but it may be different on this occasion.
Kim Yong-nam's official status is high enough to warrant a meeting with South Korean President Moon Jae-in under diplomatic protocol, said Cheong Seong-chang, analyst at the Sejong Institute think tank.
"At least in the North's party hierarchy, Kim Yong-nam is the second-highest official right below Kim Jong-un," he said. "I'd see it as a sign of determination by Kim Jong-un to improve inter-Korea ties."
If they do meet, Kim Yong-nam could invite Moon to Pyongyang for future summit with Kim Jong-un, he added.
Moon has long argued for engagement to bring the North to the negotiating table over its nuclear ambitions, which have seen it subjected to multiple sets of United Nations Security Council sanctions.
Seoul and Washington have agreed to delay annual large-scale joint military exercises which always infuriate Pyongyang, but only until the end of the Paralympics in late March.