Cheong Wa Dae (South Korean presidential office) spokesperson Kim Eui-kyeom said that Yo-jong came to South Korea as a "special envoy of Kim Jong-un". "Let us make it happen by creating the necessary conditions in the future", he was quoted as saying.
The two figures shook hands and then watched as athletes from the South and the North march together under a unified flag. "An early resumption of dialogue between the USA and the North is needed also for the development of the South-North Korean relationship", he said, according to his spokesman.
Tensions between the two soared past year as Pyongyang tested missiles capable of reaching the US mainland and its most powerful nuclear device to date, while Kim Jong Un and US President Donald Trump traded personal insults and threats of war. And they are certainly the most diplomatically fraught Olympics the world has seen in a while, coming after tense months of North Korean weapons tests and hawkish tweets from Donald Trump that set the world on edge. Some have speculated that it could contain a message from the North Korean dictator.
Pence said Moon updated him about the meeting he had with North Korean officials and "both of us reiterated to each other tonight that we will continue to stand strong and work in a coordinated way to bring maximum economic and diplomatic pressure to bear on North Korea". He has held the position for two decades.
Yo-jong's South Korea trip was especially surprising, as she is the only member of the communist state's ruling family to have visited the South, at least since the end of the 1950-53 Korean War.
Analysts believe its diplomacy is seeking to weaken the measures against it, and could be trying to loosen the alliance between Seoul and Washington.
Amid Olympic thaw, Pence says allies united in isolating North Korea
In response, the Kim regime may resume testing its nuclear and missile programs, as it has done after past Olympic détentes. He pointedly did not, though at once point he and Kim You Jong sat just feet from each other, and maybe it's just as well.
US Vice-President Mike Pence was sitting nearby when the gesture took place.
American skaters Lana Gehring and Maame Biney enjoyed the presence of the North Korean supporters.
Kim Yo Jong told Moon that relations would improve quickly once he meets with her brother. Yesterday, she joined Mr Kim Yong Nam and Mr Moon to cheer for the joint Korean women's ice hockey team as it played against Switzerland.
The delegation will return to Pyongyang later today.
He also warned that Seoul's ready acceptance of Pyongyang's overtures could damage its alliance with the US.
A South Korean and a DPRK female ice hockey player passed the Olympic flame to the final torchbearer Kim Yuna, who lit the Olympic cauldron at the main stadium.