As well as no doubt pleasing Prince William, 43, the comments by the President resulted in a sweet smile from King Charles, who looked across the table at his eldest son with affection.
The sweet moment was caught on X, with many commenting on just how proud His Majesty looks of Prince William.
One royal fan wrote on X: “King Charles looked straight at his dutiful son across the table with such a loving look. He is a very proud father.”
Another said: “I loved the proud little grin across the table.”
Someone else commented: “I see a proud Monarch and father!”
A fourth fan wrote: “King Charles has always been proud of his eldest son William.”
Prince William and Princess Kate played a big role during the state visit, along with King Charles and Queen Camilla who hosted the US President.
It is believed they all share a good bond with Trump, who is known for being a massive fan of the Royal Family. The state visit has come to an end today.