PYEONGCHANG, South Korea—North Korea has mounted a charm offensive at the Olympic Games, complete with chirpy cheerleaders, musicians and athletes—even the smiling younger sister of dictator Kim Jong Un.
But many in the South aren’t going for it.
“I think the North has fooled us enough,” said Kim A-ra, a cake-shop owner in Seoul.
Though North Korea’s outreach and South Korean President Moon Jae-in’s support for warmer ties have complicated Seoul’s alliance with the U.S., Secretary of State Rex Tillerson on Monday didn’t stand in the way of diplomacy.
Mr. Tillerson said it was too early to judge whether recent overtures would lead to a more lasting diplomatic process. And Mr. Moon hasn’t accepted an invitation to Pyongyang, saying he hoped to first create the right environment for talks.
But the prospect of a summit is deepening divisions in Seoul between those who see Pyongyang’s outreach as a ruse and those who regard accepting its invitation for high-level talks as the only way to sustain a reduction in tensions.
For Mr. Moon, spurning Pyongyang’s olive branch could risk an uptick in military activity after the Paralympics end in March—though visiting the North without making any meaningful progress on nuclear issues could further strain the alliance with the U.S.
The glow of a successful start to the Olympics, where athletes from both Koreas marched together under a unified flag, appears to have buoyed Mr. Moon, despite an enduring strain of skepticism in South Korea.
“About 80% in me is an optimist, while about 20% is a pessimist,” said Song Myeong-son, who runs a clothing shop in Seoul. “I think the young North Korean leadership will be different from their predecessors.”
On Monday, during a second straight drubbing for the unified inter-Korean women’s ice-hockey team, the mood in the arena was jubilant as dozens of North Korean cheerleaders led the crowd in chants of “We are one,” and got the wave rolling around the stands during the intermission.
During a concert by a North Korean musical ensemble in Seoul attended by Mr. Kim’s sister and Mr. Moon on Sunday, a member of one of the South’s biggest pop groups appeared on stage, holding hands with the North Koreans as they sang “Our Wish is Unification.”
On Saturday in Seoul, Kim Yo Jong, Mr. Kim’s younger sister, invited Mr. Moon to talks in Pyongyang as soon as possible for what would be only the third inter-Korean summit and the first since 2007.
“What is certain is that peace comes from talks, and that if we want peace, we can’t oppose talks,” Choo Mi-ae, the leader of Mr. Moon’s ruling party, said Monday.
Lee Jong-seok, a former South Korean unification minister, said in an interview that the North’s outreach offered a chance for Seoul to have a “candid” meeting with Mr. Kim.
Yet Pyongyang’s olive branch is prompting skepticism about how much any dialogue with the nuclear-armed regime might accomplish.
“Don’t get fooled again,” the center-right Joongang Ilbo, one of the country’s biggest newspapers, wrote in its lead editorial on Monday.
The main stumbling block: Pyongyang hasn’t demonstrated a willingness to discuss its nuclear-weapons program, whose advances in the past year have drawn increasingly stringent sanctions. The U.S., Seoul’s ally, has insisted that any resolution must begin with a demonstrated willingness from Pyongyang to denuclearize.
Even the South’s main left-leaning newspaper, Hankyoreh, which has supported the approach of the left-leaning president, has signaled a limit to its patience.
“We cannot go on forever avoiding the nuclear issue,” it said in a weekend editorial.
Kim A-ra, the cake-shop owner, said she largely supports the South Korean president, who has long sought dialogue with Pyongyang, but considers the North’s participation in the Olympics a stalling tactic so that it can advance its nuclear and missile program.
Opinion polls on the eve of the Games showed a decline in approval ratings for Mr. Moon, the first sustained slip since he took office in May. Respondents who disapproved of the president in a Gallup Korea poll taken Feb. 6-8 indicated concern over his handling of North Korea’s participation in the Olympics and his decision to form a joint women’s ice hockey team with the North.
South Korea’s Ministry of Unification addressed public skepticism on Sunday, acknowledging “significant criticism and concerns both domestically and internationally” about North Korea’s participation in the Olympics and apologizing for its “insufficient” communication.
The main conservative opposition party has said that accepting North Korea’s invitation to a summit without a commitment toward denuclearization would be treason. Conservatives have staged protests outside public events by the North Korean delegation, burning North Korean flags and tearing up pictures of Mr. Kim.
Pyongyang’s charm offensive is also highlighting differences between the approaches of South Korean and U.S. officials. Vice President Mike Pence called the inter-Korean rapprochement and the North’s participation in the Olympics, a “propaganda charade” put on by “the most tyrannical regime on the planet.”
The first time that the leaders of North and South Korea shook hands at a summit meeting in Pyongyang, in 2000, South Koreans entered from a position of strength: The previous decade had witnessed the end of the Cold War, the death of North Korea’s founder and the onset of a crippling famine that threatened to topple the North’s economy.
“Because of everything that North Korea had gone through, there was a sense that maybe the North Korean regime was changing in a major way,” said David Straub, the top political officer at the U.S. Embassy in Seoul at the time, and now a fellow at the Sejong Institute think tank in South Korea.
This time is different. North Korea has advanced its nuclear program in recent years and now boasts of being able to hit the U.S. East Coast with missiles. In September, it tested its most powerful nuclear device.
“The only thing that’s changed now is that the North has conducted more nuclear-weapons tests and fired dozens of ballistic missiles,” said Moon Seong-mook, a retired brigadier-general in the South Korean army who was involved in arranging the talks for the most recent summit in 2007.
In the North, Pyongyang’s official media has presented the recent rapprochement as a product of Mr. Kim’s magnanimity.
“Moon Jae-in said at the talk that the current visit of the delegation of the north side created a spark of improving the inter-Korean relations and ensuring peace on the Korean Peninsula and that he extends his heartfelt thanks to Chairman Kim Jong Un for providing today’s significant occasion,” the North’s state media said in a report published Sunday.
Even supporters of engagement, such as John Delury, a North Korea expert at Yonsei University in Seoul, acknowledge that the domestic mood in South Korea is far less conducive to talks this time around.
“It’s probably not good to go into this with too much euphoria,” Mr. Delury said. “North Korea will break your heart.”
—Felicia Schwartz in Cairo contributed to this article.