Joe Biden made his first overseas public speech as US President to a hangar of service personnel at an American airbase in the UK.
He arrived at RAF Mildenhall in Suffolk on Wednesday evening, ahead of the G7 Summit which starts on Friday at Carbis Bay, Cornwall.
President Biden disembarked Air Force One with his wife Jill, beginning an eight-day trip to Europe.
He said it was the "best possible way to start this trip".
The airbase was the first place outside of the United States that Joe Biden has visited since his election victory over Donald Trump last November.
He was greeted on the tarmac by senior officers from the base before getting into into his heavily-armoured presidential vehicle, known as The Beast, to be taken in convoy to a nearby open-fronted hangar.
Hundreds of troops cheered and waved miniature American flags as he took to the stage.
You might also be interested in:
The crowd, which included the service personnel's families, stood for the UK and US national anthems, before the president addressed his audience.
First Lady Jill Biden gave a brief speech in which she paid tribute to service personnel and their families, then 14-year-old Sydney Glascock, whose mother and father are both service personnel, introduced the president.
Mr Biden, who is also the Commander in Chief, told the troops in the hangar to stand "at ease", quipping: "I keep forgetting I'm president."
About 3,000 service personnel are stationed at RAF Mildenhall, where the 100th Air Refuelling Wing and the 352nd Special Operations Wing are based.
The president left the stage to more applause and waving of flags, taking time to speak to service personnel as he went.