President Donald Trump complimented Kate Middleton during the official welcome for the U.S. state visit to the U.K. on Sept. 17.

The Princess of Wales and Prince William greeted the president and first lady Melania Trump on the grounds of Windsor Castle, where the ceremonial arrival marked the start of the visit.

As they shook hands, Trump, 79, told Princess Kate, 43: “You’re beautiful, so beautiful.”

The exchange came moments after the Trumps stepped off Marine One and greeted the royal couple. Prince William, 43, guided the group forward, placing a hand on Kate and Melania’s backs as they began walking together