Crown Princess Mette-Marit makes unexpected appearance days after admitting she was 'manipulated and deceived' by Epstein

Norway's Crown Prince Haakon and Crown Princess Mette-Marit have welcomed Belgium's King and Queen to Oslo as they embark on a short state visit.

The inclusion of Mette-Marit in the program came as a surprise to many after the Royal House of Norway previously said she would not be involved due to a recent setback in her debilitating lung condition.

It has been 55 days since the Crown Princess last carried out an official engagement and Mette-Marit's first appearance since her television interview at the weekend where she spoke openly about her past friendship with Jeffrey Epstein and how she was "manipulated and deceived" by him.

Belgium's King Philippe and his wife Queen Mathilde are in Norway for a three-day official visit, aimed at strengthening ties between the two countries.

King Philippe's father, the late King Albert, was a cousin to Norway's King Harad V.

The Belgian couple was welcomed to the Royal Palace in Oslo on Tuesday by King Harald, who is 89, and his wife Queen Sonja.

King Harald recently returned from holidays in Spain where he spent several days in hospital after contracting an infection.

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Following the welcome ceremony the visiting royals posed for photos inside the palace and that is when Crown Princess Mette-Marit joined her husband, Crown Prince Haakon.

Last week, the Royal House's communications director, Guri Varpe, told the media Mette-Marit's lung condition had "deteriorated" and that she would not take part.

However, that situation changed on Tuesday when the Crown Princess appeared by her husband's side.

The 54-year-old was only at the gift exchange during the day and lunch and chose to miss the evening's state banquet.

It is not known if Mette-Marit will be included Wednesday's events.

The Crown Princess has been absent from public life because of her worsening health. Late last year, her medical team said they had begun preparations to assess the princess for a lung transplant.

She is also dealing with the ongoing situation regarding her son from a previous relationship before she married into Norway's royal family.

Marius Borg Høiby is on trial for rape and assault and the case has dominated headlines since it began on February 3.

Prosecutors have recommended he be jailed for seven years and the sentence is expected to be handed down in June.

Mette-Marit retreated from public life when the trial started and has maintained a low profile since.

The Crown Princess' past relationship with Epstein has been another issue hanging over the royal family of late after her name was mentioned more than 100 times in the recently released Epstein files.

In February, Mette-Marit issued two statements apologising for her past association with the convicted sex offender, admitting to showing "poor judgement". The situation, she said, was "simply embarrassing".

The Crown Princess had vowed to explain herself in more detail and on Friday, she did just that.

In a sit-down interview with public broadcaster NRK, Mette-Marit spoke about her emails with Epstein and staying at his Florida mansion.

"Of course, I wish I had never met him," she said.

"It is incredibly important for me to take responsibility for not checking his background more carefully. And to take responsibility for being so manipulated and deceived as I was."

One email, sent from the Crown Princess' official account, on October 23, 2011 implies she had become aware of his initial jail term in 2008.

"Googled u after last email," she wrote. "Agree didn't look too good."

She was asked about what she had Googled and found out.

"I spent a lot of time trying to figure that out myself," Mette-Marit said.

"I wish I had the rest of that email correspondence. I don't know what I found, and I don't know if it was information he had asked me to Google.

"I wish I had remembered what it was, it would probably have made my life a little easier now.

"But if I had found information that made me realise that he was an abuser and sex offender, I wouldn't have written a smiley face behind it.

"It's hard for me to say, because I can't remember. But I didn't know he was a sex offender or an abuser, if that's what you're asking."

Crown Princess Mette-Marit also spoke, briefly, about her son's criminal trial.

"We are a family that has been in a very demanding situation in recent weeks. For us, the focus has been primarily on the family.

"I am the mother of a young man who has been in a very demanding situation. In addition, I have health that requires a lot of rest . And it has developed even more."

The interview with NRK was limited to 20 minutes due to the Crown Princess being unable to speak for extended periods of time because of her lung condition.

Following the interview, an opinion poll found that 68 per cent of Norwegians did not believe their Crown Princess gave sufficient answers to the questions about Epstein.

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