The meeting, the first since December 2015, will take place in Panmunjom, the truce village in the heavily fortified Demilitarized Zone that divides the peninsula.
South Korean President Moon Jae-In said that "overly optimistic expectations" were "undesirable" but added: "We will do our best to make the Pyeongchang Olympics an Olympics for peace and settle the nuclear issue peacefully."
Tensions have been high after the North carried out multiple missile launches in 2017, including a number of ICBMs, and its sixth atomic test, by far its most powerful to date.
South Korea offers high-ranking government talks with North Korea
The tentative rapprochement comes after the North's leader Kim Jong-Un warned in his New Year speech that he had a nuclear button on his desk, but at the same time offered Seoul an olive branch, saying Pyongyang could send a team to next month's Games in the South.
Seoul responded with an offer of talks and earlier this week the hotline between them was restored after being suspended for almost two years.
Late Thursday, Moon and his US counterpart Donald Trump agreed to delay the giant Foal Eagle and Key Resolve joint military drills until after the Winter Olympics, which begin in Pyeongchang on February 9.
That announcement came hours after Trump said high-level talks between North and South would be "a good thing" - although the US has long insisted that it will not negotiate with Pyongyang unless it first takes concrete steps towards disarmament.
Seoul's unification ministry said it had received a fax from Ri Son-Gwon, head of the North's Committee for Peaceful Reunification of Korea, a state agency handling inter-Korean affairs, saying: "We will come to the Peace House at Panmunjom on January 9."
The Peace House is a South Korean-built building on the southern side of Panmunjom, where troops from the two sides face off against each other across a concrete dividing line.
Ministry spokesman Baek Tae-Hyun told journalists that the size and composition of the delegations would be settled by fax.
"I understand the North is also going to have talks with the International Olympic Committee next week," he added.
Last year saw fears of conflict spike, with Kim and Trump trading personal insults and threats of war, and the US president responded to Kim's New Year message with a Tweet that his nuclear button was "much bigger and more powerful", prompting scorn and alarm from analysts.
Concerns over North Korea have overshadowed the Winter Games, which Seoul and the organisers have proclaimed a "peace Olympics", urging Pyongyang to participate, unlike the 1988 Summer Olympics in the South, which it boycotted.
Tensions always rise during the annual drills, which Pyongyang condemns as preparations for invasion and often responds to with provocations. Beijing and Moscow both see the exercises as adding to regional tensions.
But recent days have seen a rare softening of tone on both sides.
Announcing the delay to the drills, the White House said in a statement: "The two leaders agreed to de-conflict the Olympics and our military exercises so that United States and Republic of Korea forces can focus on ensuring the security of the Games."
US Defense Secretary Jim Mattis later said the drills would take place some time after the Paralympics, which end on March 18.
He insisted the postponement was for practical rather than political reasons, citing the importance of the Olympics for South Korea's tourist industry, and added that Washington would not lower pressure on Pyongyang in other areas.
And the US ambassador to the United Nations Nikki Haley said earlier this week: "We won't take any of the talks seriously if they don't do something to ban all nuclear weapons in North Korea."
Jon Wolfsthal, former director of arms control at the National Security Council under president Barack Obama, warned that Seoul and Washington were diverging in their approach.
"US has all but forced ROK (South Korea) and President Moon to forge his own path," he said on Twitter. "Easy pickings for KJU to play the charm offensive and divide the alliance. Critical US and ROK get on same side, Trump team has to adjust."
North Korea's young leader has shrugged off multiple sets of new United Nations Security Council sanctions - including restrictions on coal sales and petroleum imports - and heightened rhetoric from Washington as his regime drives forward with its weapons programmes, which it says are intended to defend against US aggression.
North Korea's Kim Jong Un fetes rocket scientists, promises more weapons
Authorities in Pyongyang gathered thousands of citizens in Kim Il Sung Square on Thursday in a show of support for the leadership.
South Korean opposition parties struck a cautious note, warning against making concessions to the North to secure its Olympic participation.
Kim Sung-Tae, parliamentary leader of the main opposition Liberty Korea party, said a meeting about the Games without discussing denuclearisation would be "meaningless"
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