Twitter has erupted over a hilariously awkward video of President Trump tapping a child dressed up in a Despicable Me Minion costume with a bar of chocolate during a White House trick-or-treat photo session with the First Lady.

The child was among a line-up of kids in costume who trotted up to the Trumps to be given candy on Monday night.

When the president was confronted by their inflatable costume, he paused with a bar of chocolate in his hand and smiled.

Rather than toss it into the child's goody bag - as he had done with every other youngster - he tapped the head of the costume then placed the bar on top.

President Trump places a chocolate bar on the child's inflatable costume rather than putting it in their bag

Melania copied her husband and placed another full size bar of chocolate on the child's head

The couple giggled as the child walked away and watched as the two candy bars slid from the top of the costume

Melania, entertained by the bizarre gesture, did the same. As the child walked away, both of the candy bars slid off the top of the costume.

Twitter users were incredulous.

'Did these a**holes just put candy on a kid's head?' one asked.

Another quipped: 'Good god. These people can't even hand a child candy in a normal manner,' while someone else noted: 'He can't even do this right.'

Comedians including Jimmy Kimmel also noted that it was inappropriate for the White House to play Michael Jackson songs.

The late singer's legacy has taken a beating over the last year amid new allegations that he molested children. His estate furiously denies them.

At the White House event, one of the songs on a spooky playlist was Thriller.

Kimmel, a vocal critic of the president, said during his show: 'The president and first lady were there handing out candy.

'And what kind of music do you play when you have a bunch of little kids coming over? That’s right.

'Michael Jackson. I guess—maybe they don't get HBO at the White House.'