Scott Morrison has urged Australians heading overseas to be careful as the Omicron variant continues to wreck havoc with domestic and international travel.
The prime minister said while the strain's emergence was 'not a reason to step back', those leaving going abroad should make sure they follow all official government guidance.
The federal government has banned flights from nine southern African countries and delayed the re-opening of Australia's international border to skilled migrants and international students until December 15.
'Australians can still leave, although I would urge you... to be carefully considering the Smartraveller advice,' he said.
Scott Morrison speaks at Parliament House in Canberra on Tuesday. He urged Australians heading overseas to be careful as the Omicron variant global spread continues
'I look forward to everybody coming together for Christmas and New Year’s and in the summer holidays.
'Australians are continuing to return from overseas - that hasn't changed.'
Mr Morrison said the delay in opening the international border to more travellers was designed as a 'prudent and temporary pause' while officials gather more information about the Omicron strain.
'We don't know enough yet about [the strain] and the advice that I received at the National Security Committee was that this pause will provide the opportunity to understand and learn more about this,' he said.
'It is not a reason to step back.'
The prime minister said he hoped the next two weeks would show Omicron is a 'more moderate form of the virus'.
'If that is the case, then we can continue to press forward because what we are trying to do is remain safely open,' he said.
'We’re not going back to lockdowns, none of us want that. None of us want to go back to those those long quarantines and all of those sorts of issues.'
In a press conference on Tuesday morning, Chief Medical Officer Paul Kelly said doctors know the new strain, which is the most mutated so far, is 'transmissible' because it passed between hotel rooms in Hong Kong - but the severity is unknown.
But Health Minister Greg Hunt said the variant is 'manageable', adding: 'There may be milder symptoms associated with this variant but that's to be determined over the next two weeks.'
He hoped the border re-opening to students and skilled migrants will restart on December 15 after the two week pause.
'All of this is done on the presumption that we will recommence from 15 December but medical advice will guide our decision-making throughout,' he said.
The decision to pause the re-opening was made after a mammoth four-hour national security cabinet meeting of federal ministers on Monday evening.
Professor Kelly said he called for a 'temporary pause' while more data is gathered over the next 14 days.
'This is a temporary pause so we can get the information we need, but we are committed to continue to reopen. That is the advice and decisions that were made at the NSC last night,' he said.
Health Minister Greg Hunt said the variant is 'manageable' in a press conference on Tuesday
The South African province where the Omicron Covid-19 variant was first detected has suffered a more than 300 percent increase in virus related hospitalisations this week.
Gauteng, which includes the city of Johannesburg, recorded 580 hospitalizations because of the virus this week, per official data - a 330 percent jump from 135 two weeks ago.
But Professor Kelly said South Africa is not comparable with Australia because it only has a 25 per cent vaccination rate, while 87 per cent of Aussies are fully jabbed.
Travellers wait in line to verify their Covid-19 vaccination status as they check-in for a flight to Sydney, Australia on Qantas Airways in Los Angeles on November 1
On Monday as the variant spread through Europe, the UK decided to speed up its booster rollout to administer third doses three months after the second dose, instead of six months.
Australia's booster timeline is under review but Professor Kelly said the northern hemisphere needs boosters now as it heads into winter.
'We're more than six months away from winter. We know that respiratory viruses circulate a lot more in winter. It's likely that that's when we would want the boosters to be totally actively working,' he said.