Australia has officially closed its borders to all non-Australians with travellers rushing to airports in order to make the cut-off time.

Eighty per cent of Australia's COVID-19 cases are people that have been overseas or in direct contact with those who have been overseas, prompting the new rules.

The nation's borders were closed to non-residents and non-citizens on Friday night, while international flights leaving the country were grounded earlier this week.

An airport worker cleans a machine at the Qantas check-in area at Sydney Airport. (Getty)

Airports experienced chaos last night as travellers around the country rushed to made the 9pm deadline, with many making the cut-off just in time.

The Australian Government has also emphasised those still eligible to enter Australia will have to self-isolate for 14 days to slow the spread of the virus .

Australians and their direct family members will still be allowed into the country but must self-quarantine for 14 days.

READ MORE: Live updates on coronavirus

A Jetstar flight has been forced to divert to Mildura. (Nine)

People have also been urged to reconsider non-essential domestic travel and leaders will consider further health advice on this when they next meet on Tuesday, ahead of school holidays starting in early April.

They will also look at "localised responses" and what would trigger any scaled-up response needed to shut down virus outbreaks in particular suburbs or towns.

Prime Minister Scott Morrison on Friday announced stricter rules for indoor gatherings that will affect places like restaurants, pubs and cinemas.

Passengers wearing masks line up as they wait to check in at Barcelona Airport, Spain, March 14, 2020. (AP)

With the country's death toll rising to seven, indoor venues hosting non-essential gatherings will now have to make sure there are four square metres - about the size of a playground handball court - of space per person.

Outdoor events of more than 500 people were already banned and indoor gatherings restricted to 100.

The tougher rules came with stronger language from chief medical officer Brendan Murphy, who said everyone should be distancing themselves from every fellow Australian where possible.

"It's no point having a gathering of 20 people if it's in a tiny room and you're all together," he told reporters on Friday.

Social distancing means keeping a metre-and-a-half away from others, good hand hygiene, and staying home from work or the general community if you are unwell.

Eight hundred people have been infected with the virus in Australia, with almost 50 now recovered.