But the North was welcomed with open arms to what South Korean President Moon Jae-in called "Olympic games of peace".
Later, Moon watched the joint Korean women's ice hockey team - the first ever combined team at the Olympics - take on Switzerland, joining Kim Yo Jong and Kim Yong Nam, the North's nominal head of state, who is also visiting the South for the Games.
Even the dessert served at the dinner reception was symbolic, a blue chocolate map of the Koreas divided by a dark chocolate piece of barbed wire.
US Vice President Mike Pence says South Korea will continue its support of sanctions for North Korea's denuclearization.
A senior administration official said Moon did express to the vice president that he hoped there could be some potential interaction between Pence and the North Korean delegations during the games - something that did not occur.
After sitting at the table, Kim Yo Jong pulled out what appeared to be a blue document folder in front of her, which sparked the interest of the local media that speculated she might be carrying a personal message from her brother.
Saturday's meeting follows a brief encounter between the two parties Friday at the Olympics Opening Ceremony, in which Moon twice shook hands with Kim Yo Jong.
He said war had forged "the core of the bond" between the USA and South Korea and that helps explains "why there is no daylight and there will be no daylight" between the two. For the people of the Korean Peninsula, that was likely more significant than Pence's non-interaction with Kim Yo-jong. South Korean participants included senior officials Jeong Eui-yong, Jo Myong-gyoon and Im Jong-suk, the chief presidential secretary.
The younger Kim's trip to the South marks the first time that a member of the North's ruling dynasty has visited since the Korean War, which ended in an armistice in 1953. As the head of North Korea's parliament, he became the most powerful North Korean to visit their southern neighbors in 65 years, per Telegraph.
Moon and the two North Korean delegates cheerfully clapped and waved as the athletes from the two Koreas jointly marched during the ceremony holding a blue-and-white flag symbolizing a unified Korean Peninsula. They were seated beside the Moons and next to Japanese Prime Minister Shinzo Abe and his wife.
"The grievances that the world has about North Korea are very legitimate". The North also past year conducted its sixth and most powerful nuclear test to date.
The sister of North Korean leader Kim Jong Un says a summit between her brother and South Korean President Moon Jae-in would pave the way for a fast improvement in ties that would make "yesterday seem like a long time ago". The United States fought with South Korea and maintains tens of thousands of troops and an "ironclad" agreement to protect its ally. It was built in the 1960s as a luxury facility for USA troops stationed in the South.
The report from the North Korean news website also happily explained their country's involvement in some of the entertainment of the opening ceremony.
The North has sent almost 500 people to the Pyeongchang Games, including officials, athletes, artists and also a 230-member state-trained cheering group after the Koreas agreed to a series of conciliatory gestures for the games.