US 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 ambitions and human rights abuses.

Pence is in Pyeongchang to cheer on American athletes, but he is also warning the world against falling for the glossy image of the two Koreas as they 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 programme is up for negotiation.

Pence said the US would “demand at the outset of any new dialogue or negotiations that the Kim regime put denuclearisation on the table and take concrete steps with the world community to dismantle, permanently and irreversibly, their nuclear and ballistic missile programmes”.

He added: “Then and only then will the world community consider negotiating and making changes in the sanctions regime that’s placed on them today.”

The US vice-president 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 US 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.

Pence seeks to counter what he called North Korean “propaganda” around the Winter Olympics, and is eager to put a reality check on the thaw in relations between the Koreas in advance of the Games. He met North Korean defectors and paid respects at the Cheonan Memorial in Pyeongtaek, which honours the 46 South Korean sailors killed in a 2010 torpedo attack blamed on the North.

Pence warned that the world would see “a charm offensive by North Korea”.