Sources: 

King Charles III's lighthearted jibe at President Trump during a state dinner celebrated the enduring UK-US partnership. Joking that without British support, the U.S. would be speaking French, the King also highlighted historical defense contributions in the face of contemporary global threats.
The King's comments referenced Trump's earlier statement about European nations relying on the U.S. for defense since WWII, where Trump claimed that without American support, they would be speaking German. In a warm atmosphere of camaraderie, Charles managed to deliver a series of acknowledgments to U.S.-UK ties, resulting in several standing ovations from lawmakers during his speech the following day.
"We meet in times of great uncertainty, in times of conflict from Europe to the Middle East which pose immense challenges," he said, underlining the partnership's significance.
The King's emphasis on shared defense interests is critical as he remarked,
"Our country, in order to be fit for the future, has committed to the biggest sustained increase in defence spending since the Cold War," indicating a strong commitment to international security. Charles also underscored the value of understanding and respecting diverse beliefs, calling for unity amid global unpredictability, particularly in the Middle East. His visit was historic, marking the first such address to Congress from a British monarch in 35 years, emphasizing modern benefits from an established alliance.
Sources: 
King Charles III humorously told President Trump at a state dinner that without British aid, Americans would be speaking French, referencing Trump's past comments on European defense. The King's address received multiple standing ovations as he emphasized the vital UK-US partnership amid global challenges.