Donald Trump has been mercilessly mocked online after he posted a rambling and misspelled late night tweet - just hours after Press Secretary Sean Spicer fled his first press conference since the president returned to the US amid a reporter revolt.

'Despite the constant negative press covfefe', President Trump tweeted after midnight on Tuesday.

'Covfefe' has since become the top trending topic in the US as thousands of hilarious memes flooded Twitter to mock the bizarre tweet.

'Despite the constant negative press covfefe', the president tweeted after midnight on Tuesday

Donald Trump (pictured) has been mercilessly mocked online after he posted a rambling and misspelled late night tweet just hours after Press Secretary Sean Spicer's debacle

Many joked the half-finished tweet, which has not yet been deleted, was the result of one of Trump's aides ripping his phone from his hands.

Others claimed it was a new take on Trump's famous slogan, which is now: 'Make America covfefe again!'

Some expressed concern for the president, suggesting he may have had a 'stroke' mid-type, while others wanted to know why no one at the White House appeared to have noticed the tweet for at least an hour.

'Is everyone in the White House asleep right now???' one user tweeted.

'It's the new upcoming Starbucks drinks. It's orange vanilla with a borscht swirl. They make the whip cream look like a white hood,' another joked.

Twitter users attempted to find some meaning behind covfefe - leading to a heated exchange between a wizard and a viking warrior who claimed to have been summoned in order to search for a mythical orb

The comment has sparked both confusion and hundreds of memes mocking the bizarre tweet

Elyse Johnson‏ added: 'Maybe she's born with it, maybe it's #Covfefe.'

Other tweets joked 'covfefe' could be anything from the nuclear launch codes to the title of a new release at cinemas soon, to the thing you make when life gives you lemons.

The businessman-turned-politician appears to have been writing 'despite the constant negative press coverage...' but we may never know what then end of that sentence should have been.

Of course, it is not the first time someone in Trump's administration has made a Twitter blunder.

White House press secretary Spicer posted what appeared to be a random assortment of letters and numbers in January - which many took to be his password or joked it could be the nuclear codes.

Trump's rambling tweet on Tuesday night came just hours after Spicer dramatically exited the White House press briefing - his first day back at the podium since the president returned from his overseas trip - amid a reporter revolt over his attack on 'fake news'.

Many joked the half-finished tweet, which has not yet been deleted, was the result of one of Trump's aides ripping his phone from his hands

The press secretary abruptly ended the briefing after three news outlets the president has called 'fake news' and 'the enemy of the American people' pressed the Trump spokesman on his claims and demanded he provide a list of stories the White House believes to be false.

'What I'm telling you is that the reason the president is frustrated is the perpetration of false narratives, the use of unnamed sources over and over again about things that are happening that don't ultimately happen and I think that is troubling,' Spicer said in his final word on the topic.

Packing up, Spicer told the room, 'thank you, guys, very much,' and left amid yelling, and some booing.

Spicer appears to be in hiding after the debacle, with Wednesday's press gaggle due to be held off-camera, according to the White House's daily press schedule.