"We should firmly keep in mind that any talks where denuclearisation is not a precondition only to buy North Korea more time to complete its nuclear capabilities while they fool us with their peace offensive facade", party spokesman Chang Je-won said, according to Reuters.
Last month, a White House official told reporters Pence would attend the Winter Olympics opening to cheer American athletes and to counter any North Korean effort to "hijack" the games with a propaganda campaign.
The US has been cautious about the invitation, with vice president Mike Pence also in South Korea to warn the country against "falling for" the North's overtures. Kim Jong-un's wife was a member of the squad that came in 2005.
As it turned out, with the two Koreas celebrating a moment of unity, the United States was left outmanoeuvred by an adversary and out of step with an ally.More news: South Africa's ruling ANC to finalise talks on Zuma's future
It's by far the most sustained public presence for Kim, who had been something of a mystery to many South Koreans, despite her known role in North Korea's politburo.
At the age of 30, Kim Yo Jong is probably the most powerful woman in North Korea.
Kim Yo-Jong, the sister of North Korea's leader Kim Jong-un, arrives at the Presidential Blue House in Seoul, South Korea, February 10, 2018.
The diplomatic honor bestowed upon North Korea was rare: Moon met Kim Yo Jong, the first member of the North's ruling dynasty to have visited South Korea, four times during the trip.
In an exclusive interview with NBC News' Lester Holt on the sidelines of the PyeongChang Winter Olympics, Warmbier said he did not find it hard seeing North Korean leader Kim Jong Un's sister enjoying the moment at Friday's Opening Ceremony. Kim Yo Jong offered an invitation from her brother for Moon to visit the North, in the strongest sign yet of an expanding diplomatic opening opposed by the U.S.
Speaking to the Washington Post's Josh Rogin aboard Air Force Two on his flight home, Pence said the United States would participate in direct talks with North Korea's leadership without preconditions - something experts have long urged the administration to do.More news: Shoppers 'vote with wallets' as Aldi tops survey
US 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.
They have shared kimchi and soju with Moon, sat in the same box at the Olympics opening ceremony and cheered a unified women's ice hockey team together.
Pence said Friday that the USA would oppose talks between the two Koreas until the North agreed to open negotiations on ending its nuclear program. There were rumblings of discontent over having to drop players to add the North Koreans, and of being pawns in a game they did not want to play. Almost 200 female members of the North Korean cheerleading regime - a handpicked group created to be an appealing propaganda arm of the ruling party - chanted and sang (and did the wave on several occasions) while other fans clapped along in between Switzerland's offensive barrages.
"We have to be unified (with North Korea)".
Along with the rest of the North's senior delegation, Kim is to have lunch with Moon in Seoul.More news: Barnaby Joyce 'resisted' removing girlfriend Vikki Campion from office
- NASA probe "New Horizons" snaps farthest-ever photo from Earth
- 'Frank, candid' talks held with Moon, says Pyongyang
- Dutchman claims third straight gold
- Gophers ladies crush Penn State, begin homestand on excessive be aware
- Gigi Hadid slams body shamers
- United Nations chief urges dialogue in talks with North Korean official
- Fiorentina-Juventus, le probabili formazioni. Marchisio dal 1′
- Philippines Bars Citizens From Working in Kuwait, Citing Abuses
- Kim Jong-Un Invites South Korea's President To Summit Meeting
- In Interview, Trump Casts Doubt on Palestinians' Desire to Make Peace