'

President Donald Trump earlier called him "the greatest king in my book", as he said farewell to the King and Queen at the White House

The official goodbye showed the pair's different approaches, our royal correspondent writes - Trump was happy to chat in front of the camera, while the King seemed less enchanted

On their last day in the US, the royals met locals in the town of Front Royal in Virginia - the King also laid a wreath at the Tomb of the Unknown Soldier at Arlington National Cemetery

The King's plane will be heading to Bermuda - a British overseas territory, where he is head of state

King Charles boards plane as he departs US. 00:00:36, play video

King Charles boards plane as he departs US

King Charles stands in the doorway of a white airplane with the British flag on it as he waves.

Among the first notable guests to arrive were tech leaders who had earlier met with the King at Blair House, where the president's guests traditionally stay.

Jeff Bezos in white tie and tuxedo, accompanied by his wife Lauren Sanchez in a formal black gown, walk between violinists outside the White House

Image source,Reuters

Image caption,

Amazon and Blue Origin founder Jeff Bezos, accompanied by his wife Lauren Sanchez

Apple CEO in white tie surrounded by a group of men in suits

Image source,Reuters

Image caption,

Apple CEO Tim Cook is escorted through a crowd towards the White House

US lawmakers who listened to King Charles' speech are now giving their reactions.

Senate Minority Leader Chuck Schumer, a Democrat, says the speech should serve as a "reminder" to President Donald Trump that "friends and allies matter".

"It has been thirty-five years since a British monarch addressed the elected representatives of the American people—the world has changed dramatically, but in many ways, the same tests remain before us," he writes on social media.

Senate Majority Leader John Thune says he was "honoured to welcome King Charles III and Queen Camilla to the Capitol as a part of our America 250 celebration." Thune and Schumer were among the group of lawmakers who escorted the royals into the chamber.

Republican Senator Lindsay Graham says the speech was a "terrific combo of wit, humour, history and appreciation." He posted on X that it was a morale-boost, adding that "it was a bit odd that the unifying feeling had to come from the King of England… but so be it!"

Earlier, while the King and the president met in the Oval Office, Queen Camilla and First Lady Melania Trump spoke to a group of schoolchildren about AI and virtual reality.

The first lady spoke to the kids about British and American history and how they need not travel far to learn about it.

“Today, students all over the world can visit historically important sites, learn about the past, and be inspired,” Melania Trump said, according to a press release by her office. “Our children don’t need to board airplanes to experience history anymore. Kids can have an educational experience that is fundamentally richer and more memorable than ever before, through VR and AI.”

Students explored historical UK sites, such as Buckingham Palace, using Meta VR headsets, the release said.

The students also used the headsets to view historical objects brought in by the first lady, including a portrait of the second US President, John Adams, who was the first US ambassador to the UK, as well as a bust of Winston Churchill.

After addressing Congress and prior to tonight's White House dinner, the King is also meeting with the heads of major technology companies as part of his state visit.

In photos of the intimate event at Blair House, across from the White House, the King can be seen in photos speaking with outgoing Apple CEO Tim Cook and Salesforce CEO Marc Benioff.

Amazon CEO Jeff Bezos and Ruth Porat, president and CIO of Google's parent company Alphabet, are also in attendance.

The King is accompanied by Varun Chandra, the prime minister's special envoy to the US on trade and investment. (BBC)