The first medals of the Pyeongchang Olympics will be awarded Saturday, but most attention will be focused on a preliminary round hockey match featuring the combined Korean women's hockey team.
USA officials have been urging South Korea to be cautious in its rapprochement with the North - a point Pence drilled home in private meetings with Moon on Thursday.
The pranksters made their appearance as war threatens to break out between the US, North Korea and South Korea.
Seoul's Unification Ministry said Friday that the Mangyongbong-92 will return to the North on Saturday.
Such a high-level meeting would have been unthinkable even a few months ago, but 2018 has seen an accelerated rapprochement between the two adversaries in the run up to the PyeongChang Games, the CNN report said.
South Korea says the artists will return to the North on Tuesday by a land route.
South Korea treated the ferry as an exception to maritime sanctions it imposed on the North so it could transport the artists to the South.
Pence and Japanese Prime Minister Shinzo Abe sat nearby, looking expressionless.
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And when captain Rory Best went over for Ireland's sixth try, the visitors were facing a humiliating defeat. Get your weekend sorted with our guide to live streaming the Ireland vs Italy Six Nations 2018 match.
Moon and Kim Yong Nam were due to be in the stands as well, a Blue House spokesperson told CNN. The North Koreans were in the room at the same time as Pence, an official said.
"The North Koreans should understand that for a summit or any kind of serious talks to occur, Moon needs to be able to take something to Washington - something that addresses denuclearization", he said before the North's invitation to Moon was announced.
Moon is desperate to use the games as an opportunity to restore regular communication with North Korea and eventually pull it into talks over resolving the global stand-off over its nuclear program. They stressed the North Koreans in the VIP box had watched Pence, Moon and Abe hold a running discussion in the front row for the more than two-hour ceremonies.
Moon said improved relations between the Koreas may be a step toward resolving the nuclear standoff.
U.S. Vice President Mike Pence is not directly addressing news that North Korean dictator Kim Jong Un has invited South Korean President Moon Jae-in for a visit, as the two Koreas use the Olympics as an opportunity for renewing ties. The North Korean delegation that arrived in the South on leader Kim Jong Un's private jet also includes his sister Kim Yo Jong.
The lunch at the Blue House came after Kim Yo Jong and other North Korean delegates attended the opening ceremony of the Pyeongchang Winter Olympics, which has brought a temporary lull in tensions over the North's nuclear program.
In the meeting, Kim Yo Jong reportedly handed Moon a letter from her brother, and asked the president to visit the North at the earliest possible date.