This week, Moon received an invitation from his northern counterpart, Kim Jong-un to visit Pyongyang for a top-level summit.
Some in South Korea disagree with that approach.
At Friday's opening ceremony, Pence was seated just one row in front of a North Korean delegation that included Yo Jong and Yong Nam, and had no interaction with them.More news: Safe return needed for Rohingya refugees - Johnson
Pence rode to the reception with Japanese Prime Minister Shinzo Abe, and the two held a private conversation while waiting more than 10 minutes for a photo opportunity with Moon. Later, he skipped a formal dinner at which he was due to share a table with North Korea's ceremonial head of state Kim Yong Nam.
A senior U.S. official said Pence and Moon, while watching speed skating together on Saturday night, discussed intensifying sanctions.
The recent detente, anchored by South Korea's hosting of the Winter Olympic Games, came despite an acceleration in the North's weapons program previous year and pressure from Seoul's allies in Washington.
Moon said improved relations between the Koreas may be a step toward resolving the nuclear standoff.
He pointed to his belief that economic pressure "contributed" to the North's "outreach" to the South regarding the Olympics, and that a new round of sanctions might help the regime move toward a "future without nuclear weapons".More news: Man City's Aguero routs Leicester with 4 goals
North Korea conducted its largest nuclear test a year ago and said it had developed a missile capable of carrying a warhead to the United States. North Korea is likely advancing its own strategic interests by playing into Moon's vision of a peaceful Korean Peninsula. The North Korean delegation that arrived in the South on leader Kim Jong Un's private jet also includes his sister Kim Yo Jong.
A sense of détente, at least for the time being, prevailed in and around the Pyeongchang Olympic Stadium Friday as the Winter Games opened in a ceremony where North and South Korean athletes marched under a unified flag. She was photographed sitting behind Vice President Mike Pence during the ceremony. White House officials stressed that Pence had applauded only for the American team, but Asia experts said the vice president's refusal to stand could be seen as disrespectful to the hosts. It was handed to South Korea's president by Kim's sister, acting as an envoy.
The countries are still technically at war since their 1950-53 war ended in a truce rather than a peace treaty. Dozens of South Koreans at the airport tried to snap photographs of her on their mobile phones.More news: Mkhitaryan has no excuses for United struggles
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