At the Winter Olympics, much of the world has been captivated by the joint Korean women's ice hockey team and the presence of Kim Jong-Un's sister, Kim Yo-jong, in Pyeongchang.

CNN ran a controversial headline that read: 'Kim Jong Un's Sister Is Stealing the Show at the Winter Olympics.'

And one American member of the International Olympic Community has even suggested the joint Korean team should be nominated for a Nobel Peace Prize.

But it is time to get serious, according to the Christian persecution advocacy group Open Doors. The organisation has warned people not to be fooled by the show of unity between North and South Korea at the games and forget the multiple, horrific human rights abuses under the regime of Kim Jong-Un.

'As many nations come together to take part in the Winter Olympics, let us not forget that every day over 300,000 Christians [in North Korea] are denied the right to take part in the religious observance of their choice,' said Matthew Rees, advocacy policy officer at Open Doors, in a statement. 'They are a beleaguered community who are fighting for their very survival.'

Open Doors emphasised that 'every aspect of life in North Korea is controlled by the state'. North Korea is number 1 on the 2018 Open Doors World Watch List and has been so for the past 16 years.

'The belief that God is a higher authority than the nation's leader, Kim Jong-un, is seen as a threat that must be crushed,' said Open Doors. 'Tens of thousands of Christians are incarcerated in horrific labour camps, and thousands more keep their faith in Christ a complete secret.'

Open Doors highlighted Christian defectors from the regime. 'They ignore all freedoms,' said Timothy, a North Korean refugee, according to the charity. 'The human rights level is zero percent. Religions are not allowed. The leader of North Korea has to be worshipped as god, and this will not change unless the regime collapses.'

The comments came as the US Vice President Mike Pence traveled to South Korea and met with a group of North Korean defectors on Friday. He was accompanied by the father of Otto Warmbier, the American man who died after being jailed for months in North Korea and sent home last year in a brain-dead state.

Pence warned that the world would see 'a charm offensive by North Korea' at the Olympic games. He had previously warned that North Korea would try to 'hijack the message and imagery' of the Olympics and stressed that the world should not let North Korea hide behind the Olympic banner.

Pence said: 'The cruel dictatorship of NK is little more than a prison state. As people testified, it is a regime that imprisons, tortures and impoverishes its citizens and I can assure your witness of that truth will be heard across the world. Thank you for your courage and I look forward to discussing further.'

On Saturday, Pence met with the South Korean President Moon Jae-in and told the press that 'both of us reiterated to each other tonight that we will continue to stand strong and work in a coordinated way to bring maximum economic and diplomatic pressure to bear on North Korea'.