US VICE-PRESIDENT Mike Pence was left out in the cold in South Korea over the weekend, as his efforts to prevent any thaw on the peninsula were given a frosty reception.

Pence spent the days leading up to the Games warning that the North was trying to “hijack the message and imagery of the Olympic Games” with its “propaganda.”

But the North was still welcomed with open arms to what South Korean President Moon Jae In called the “Olympic games of peace.”

Moon was all smiles Saturday as he greeted Kim Yo Jong, the sister of North Korean leader Kim Jong Un, and Kim Yong Nam, the country’s 90-year-old nominal head of state, for lunch at the presidential residence.

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 US.

Pence said on Friday that the US would oppose talks between the two Koreas until the North agreed to open negotiations on ending its nuclear programme, and he was silent Saturday on the news of the invitation.

Moon and Pence spoke on Saturday while taking in the speedskating, but aides did not immediately say whether the invitation came up during the discussion.

At the opening ceremonies on Friday, Pence sat stone-faced in his seat as Moon and North Korean officials stood together with much of the stadium to applaud their joint team of athletes. 

White House officials claimed that Pence had only clapped the US team.

Even Japanese Prime Minister Shinzo Abe, who has obediently echoed US opposition to warming relations, greeted Kim Yong Nam.

US officials denied that Pence had been blindsided by the seating arrangements: the North Koreans were in the row behind him, allowing Kim Yo Jong to be easily pictured in profile next to the vice president.

• OLYMPIC organisers are investigating a possible attack on their internet systems that took place about 45 minutes before the opening ceremony.

Organising committee spokeswoman Nancy Park said the defence ministry and a cybersecurity team were investigating the Friday night outage.