Donald Trump was accused of greeting The Queen with a fist-bump at Buckingham Palace today.
Footage from the meeting shows the US President reach out his hand to shake the monarch's hand at around 12.30pm.
The pair shook hands but the camera angle and bizarre-looking method left social media users baffled.
Some on Twitter even claimed Mr Trump, 72, "fist-bumped" the Queen.
"Did...did that man just fist-bump our Sovereign? Get him on the block," wrote one man on the social media platform.
Others were also outraged at what they saw as another Trump "howler".
"Trying to work this out. Is it a hand shake and fist-bump howler," another user posted.
"At first I thought they were fist-bumping," one man wrote online.
When the royal party and their guests stepped from the palace, the American national anthem was played and Mr Trump was invited to inspect the guard of honour.
Prince Charles accompanied the president as he strode onto the lawns to inspect the waiting troops formed up in two lines with the guardsmen wearing their famous scarlet tunics and bearskins.
Among the soldiers, who when not performing ceremonial duties are fighting servicemen, was Guardsman Joshua Young-Hastings from Wandsworth, southwest London.
He was the tallest soldier in the guard of honour and played American Football for the London Warriors before joining the Army.
The guardsman was scouted for a professional career with America's National Football League and was awarded a half scholarship with a Texas university but chose the Grenadier Guards over a sporting career.
But protesters gathered outside the palace.
Auriel Glanville dressed up in a costume she called "the statue of taking liberties", outside Buckingham Palace
The 76-year-old, from London, said: "Donald Trump is a climate change denier.
"He's a very dangerous man.
"He's not listening to any of the scientists or David Attenborough that climate change is being caused by human activity.
She said she did not think it was right that Mr Trump was allowed to make a state visit, adding: "Climate change is at the top of the agenda and he's not addressing that."
Ms Glanville said she hopes Mr Trump's meeting with the Prince of Wales later will be an opportunity to bring up the issue of climate change.
