On Friday evening, the North Korean visitors are expected to join foreign dignitaries, including Vice President Mike Pence and Prime Minister Shinzo Abe of Japan, at the opening ceremony of the Winter Olympics being held in the South Korean town of Pyeongchang.
The convergence of political figures raises the possibility of extraordinary diplomatic encounters between the North Koreans and the leaders of their sworn enemies.
President Moon Jae-in has said he will host a luncheon for the North Koreans on Saturday. It was unclear whether Mr. Moon, a dogged proponent of dialogue with North Korea, would try to broker a meeting between Mr. Pence and the North Koreans.
For his part, Mr. Pence has said he would use his visit to counter the North’s propaganda and remind the world of its abuses and atrocities. On Friday, he met with defectors from the North and with Fred Warmbier, an American whose son Otto died last year after months of imprisonment in the North.
They met at a memorial to the Cheonan, a South Korean warship sunk in 2010 by what is widely believed to have been a North Korean torpedo. One of the defectors, Ji Seong-ho, who was a guest at President Trump’s State of the Union address last month, became visibly emotional and embraced Mr. Warmbier three times.
Another defector, Lee Hyeon-seo, said that the news media should focus on the impoverished people of North Korea struggling to survive a harsh winter, and not on the Olympics.
Kim Jong-un rattled the world last year by accelerating his efforts to build a nuclear missile capable of reaching the United States mainland. He tested a series of long-range missiles and conducted his country’s most powerful nuclear test.
After ignoring Mr. Moon’s repeated invitations to the Olympics, Mr. Kim in a New Year’s Day speech surprisingly proposed sending North Korean athletes to the Games — while at the same time claiming to have a “nuclear button” on his desk that could launch missiles capable of reaching the continental United States.
The Olympics gesture set off a series of talks and agreements between the two Koreas, which have dominated headlines in the weeks leading up to the Olympics. Both Koreas agreed to march together in the opening ceremony and compete side by side in women’s ice hockey, forming their first joint Olympic team. Hundreds of musicians and singers from the North have arrived to perform on the sidelines of the Olympic Games.
Ms. Kim’s appearance in South Korea will be a rare instance of high-level inter-Korean contact. She is not believed to have ever before met a South Korean official.
In 2000, her father, Kim Jong-il, held a summit meeting with Kim Dae-jung, then South Korea’s president, but he did not keep his promise to visit the South for a second meeting. In 2007, Roh Moo-hyun, then the South’s president, visited North Korea for the second inter-Korean summit meeting.
Kim Jong-il died in 2011 and power was passed to his third son, Kim Jong-un.
Ms. Kim and another member of the North Korean delegation, Choe Hwi, were blacklisted by the United States Treasury in January 2017 over allegations of involvement in “serious human rights abuses and censorship activities.” Ms. Kim is believed to be a first vice director of the ruling Workers’ Party’s Propaganda and Agitation Department, which is responsible for censorship of newspapers and broadcast media.
Last June, the United Nations Security Council included Mr. Choe in a list of 14 North Korean officials designated for an asset freeze and travel ban for their involvement in the North’s nuclear weapons program. Mr. Choe is visiting South Korea as chairman of the North’s National Sports Guidance Committee.
It was unclear whether Mr. Kim was sending a message to Mr. Moon through his sister. Mr. Moon has said he is willing to meet Mr. Kim if he is reasonably sure that such a meeting would help end the crisis over the North’s nuclear weapons and missile development program.