Mr Trump is expected to deliver the traditional speech at the state banquet held in his honour by the King and Queen when he arrives.
A source who is close to the King told the Daily Beast: “Charles has spent his entire life promoting tolerance and compassion.
“He will be appalled by what Trump said on Friday, which seems to be entirely driven by his domestic agenda, and will be very concerned about the possibility of a repeat of Trump’s outburst in September.”
They added that aides fear the US president might give an impromptu interview to the media with political statements, which could put the monarch in a difficult position.
They said: “If Trump starts sounding off about the evils of immigration to the cameras while the King is standing next to him, the King would find that hard to take.”
Buckingham Palace has been contacted for comment.