Prince Harry's surprise appearance on The Late Show with Stephen Colbert saw him make a subtle jab at Donald Trump.

The Duke of Sussex appeared in a sketch with the talk show host mocking Hallmark Christmas movies, cheaply made festive films which are mass-released around the holiday season. Prince Harry had jokingly asked when he would be featured as a prince in a Hallmark Christmas film, but also passed comment on the president's administration.

Prince Harry walked into shot mid-monologue to a standing ovation and joked he had been looking for an audition space for Hallmark Christmas movies. He said, "I genuinely thought this was the audition for the Gingerbread Prince Saves Christmas in Nebraska."

Colbert and Prince Harry went back and forth on why the Duke of Sussex would want to appear in a Hallmark Christmas film. Prince Harry replied, "Well, you Americans are obsessed with Christmas movies and you're clearly obsessed with royalty, so why not? ... I heard you elected a king?"

Some viewers believed this was a knock at Trump over the No Kings protests which were held across America earlier this year. The No Kings protests were a series of demonstrations against what has been viewed as authoritarianism and corruption in Trump's administration.

Trump had been referred to by some protestors as a king, with signs reading "No Kings Since 1776" referencing the year the US declared independence from the UK.

The president responded to these comments and said he was "not a king at all", The Guardian reported. He said, "They say they’re referring to me as a king. I’m not a king."

"I’m not a king. I work my a** off to make our country great. That’s all it is. I’m not a king at all. The demonstrations were very small, very ineffective, and the people were whacked out. When you look at those people, they are not representative of the people of our country."