Politics
“Quite frankly, the only thing age brings is a little bit of wisdom,” the president said in an interview set to air Wednesday night.
The foreign secretary also said he "gets on" with the former president's running mate JD Vance.
The prime minister says he wants to "renew our relationship" with the EU.
"It was a funny thing to do, but it was a serious thing because of the tragedy that happened," one attendee said.
The 81-year-old president was campaigning earlier in the day.
"Before you know it, you have a bright future behind you," the ex-PM joked.
The former prime minister is angry at being included in a briefing pack for the King's Speech.
"Have you considered writing to your MP about it?"
Charles has one of the most famous hereditary positions in the world.
The president's reelection campaign has come under scrutiny following his poor performance at a CNN debate late last month.