World tennis No 1 Novak Djokovic has been told his visa has been refused and he has been asked to leave Australia later today, the Australian Border Force says.

Djokovic had been given a medical exemption to meet Australia's Covid-19 vaccination requirements so he could defend his Australian Open title but it prompted an incensed reaction from many around Australia.

The Australian Border Force said in a statement this morning that Djokovic has been told his visa has been refused and he has been asked to leave the country later today.

The ABF said Djokovic had failed to provide appropriate evidence to meet the entry requirements to Australia, and that his visa had subsequently been cancelled.

"This evidence is required to be presented at the border by unvaccinated people," the statement said.

The statement said non-citizens who do not hold a valid visa on entry or who have had their visa cancelled will be detained and removed from Australia.

Australian Prime Minister Scott Morrison has confirmed that Djokovic's visa has been cancelled and he won't be allowed to enter the country.

"Mr Djokovic's visa has been cancelled. Rules are rules, especially when it comes to our borders. No one is above these rules. Our strong border policies have been critical to Australia having one of the lowest death rates in the world from COVID, we are continuing to be vigilant," Morrison wrote on Twitter.

Meanwhile, Serbia's President Aleksandar Vučić has vowed to "fight" for Djokovic to be able to enter Australia.

He wrote on Instagram that he had spoken to Djokovic and vowed to use all diplomatic avenues available to Serbia to help the player.

"I told our Novak that the whole of Serbia is with him," Vučić wrote.

"Our bodies are doing everything to see that the harassment of the world's best tennis player is brought to an end, immediately."

The ABC reported that the 34-year-old Serbian is being taken to an immigration hotel in Melbourne.

It's expected he will challenge the visa cancellation in Australia's Federal Court.

Earlier today Reuters reported that Djokovic had been left stranded in a Melbourne airport lounge overnight.

Djokovic landed in Melbourne late last night in the middle of a political maelstrom over his medical exemption from Covid-19 vaccination requirements, with a visa blunder adding to the world number one's problems ahead of the Australian Open.

Djokovic touched down at Tullamarine airport at about 11.30pm local time, but had to await permission to enter the country after it emerged that his team had applied for a visa that does not allow for medical exemptions.

That prompted the local government of Victoria, the state where the Open is played, to say it would not support Djokovic's application, putting his fate in the hands of the federal government and Prime Minister Scott Morrison.

Morrison has faced an enormous backlash over his government's decision to grant Djokovic a medical exemption from vaccination to play at the Open, where the player would be bidding for a record 21st major title.

Australia, especially the state of Victoria, has endured the world's longest cumulative lockdown and an outbreak of the Omicron variant has sent case numbers to record levels.

Following the backlash, Morrison suggested Djokovic's participation was not a done deal and he would have to satisfy the federal government, which has responsibility for international borders and visas and was not part of the exemption process.

Morrison said shortly before Djokovic's arrival that there would be "no special rules" for him on his exemption.

"If that evidence is insufficient, then he won't be treated any different to anyone else and he'll be on the next plane home," Morrison told a media conference earlier.

Visa bungle

Djokovic came in on an Emirates flight but when border officials contacted the Victorian government to ask if the state would formally support the world number one's visa, it said it wouldn't.

"The Federal Government has asked if we will support Novak Djokovic's visa application to enter Australia," Victoria's acting Sports Minister Jaala Pulford said.

"We will not be providing Novak Djokovic with individual visa application support to participate in the 2022 Australian Open Grand Slam.

"We've always been clear on two points: visa approvals are a matter for the federal government, and medical exemptions are a matter for doctors."

It was not clear whether the federal government would allow his entry. The Border Force could not be reached for comment.

Tennis Australia and government officials moved quickly to stress that Djokovic, who has said he is opposed to Covid-19 vaccinations, had received no preferential treatment.

Angry Aussies

Djokovic, who has won nine titles at Melbourne Park including the last three, confirmed on Wednesday that had received a vaccination exemption to allow him to play at the Australian Open, which starts on 17 January.

Australian tennis great Rod Laver, after whom the main showcourt at Melbourne Park in the state of Victoria is named, warned that Djokovic might face hostility from the local crowd.

"I think it might get ugly," Laver told News Corp. "I'd think the Victorian people would be thinking 'Yes I'd love to see him play and compete, but at the same time there's a right way and a wrong way.'

"Yes, you're a great player and you've performed and won so many tournaments, so it can't be physical. So what is the problem?"

Melbourne local Christine Wharton said it was a "disgrace".

"We've all done the right thing, we've all gone out and got our jabs and our boosters, and we have someone that's come from overseas and all of a sudden he's been exempt and can play, and I think it's an absolute disgrace and I won't be watching it."

-Reuters