PYEONGCHANG, South Korea — U.S. Vice President Mike Pence is using his appearance at the Winter Olympics to call on the international community to get tougher on North Korea's nuclear program and human rights abuses.

Pence arrived Friday in Pyeongchang to cheer on American athletes, but said he is warning the world against falling for the glossy image of the two Koreas as they are set to march in the opening ceremony under one flag.

After meetings with South Korean President Moon Jae-in and Japanese Prime Minister Shinzo Abe, Pence said there should be no consideration of using the Games as an opening for substantive talks with the North until its nuclear program is up for negotiations.

Pence said the U.S. would "demand at the outset of any new dialogue or negotiations that the Kim regime put denuclearization on the table and take concrete steps with the world community to dismantle, permanently and irreversibly, their nuclear and ballistic missile programs."

"Then and only then will the world community consider negotiating and making changes in the sanctions regime that's placed on them today," he added.

Pence is in Pyeongchang at the same time as a high-level North Korean delegation including leader Kim Jong Un's sister, Kim Yo Jong, and nominal head of state Kim Yong Nam.

Pence has repeatedly left open the possibility of an encounter at the Games, but said the U.S. had not requested a meeting.

At a VIP reception before the opening ceremony, Pence and Kim Yong Nam were in the same room, according to Jarrod Agen, his deputy chief of staff, but Pence "did not come across the North Korean delegation" at the event.

As he seeks to counter what he called North Korean "propaganda" around the Winter Olympics, Pence has filled the days leading up to the Games with his own symbolism and rhetoric.

Eager to put a reality check on the thaw in relations between the Koreas in advance of the Games, Pence met with North Korean defectors Friday and paid respects at the Cheonan Memorial in Pyeongtaek, which honors the 46 South Korean sailors killed in a 2010 torpedo attack blamed on the North.

During his meeting with the four defectors, including some who had been tortured and abused by the North, Pence warned that the world would see "a charm offensive by North Korea" on Friday. "But today we thought it was important to make sure the truth is told."

"As these people and their lives testify, it is a regime that imprisons, and tortures, and impoverishes its citizens," he added.

Pence avoided public criticism of Moon, congratulating South Korea on hosting the Olympics and pledging continued support in addressing the North's nuclear threat. But privately, officials said, Pence expressed concern to Moon about his more conciliatory tone toward North Korea.

"President Moon and President Trump are completely aligned in their objective for a nuclear free Korean Peninsula," Pence said. But the two leaders appear to differ on the path to get there.

Moon has embraced the Games as an opportunity for a thaw in tensions, calling them "Olympic Games of peace." The opening ceremony will be attended by the North Korean leader's sister and other senior officials. And women's ice hockey players from both Koreas will compete as one team.

As he met with Pence on Thursday, Moon added his hope that it becomes "a venue that leads to dialogue for the denuclearization of the Korean Peninsula."