Health Minister Rachel Stephen-Smith said there were now 40 active cases, with 200 people who might have been in close contact with people who had the highly infectious variant.

The previous statistic was 35 cases of the variant which is estimated to be at least three times more infectious than previous ones, including Delta. Some estimates make its infectiousness even greater.

Ms Stephen-Smith said there was a surge in people seeking testing over the weekend, and that drive to process tests was disrupted when the storm forced the temporary closure of one site.

There were 1200 tests at the Mitchell drive-through site on Saturday even though testing was disrupted by the storm. Garran and Dickson sites processed 900 tests each on Sunday, according to the health minister.

Despite the apparent arrival in strength of the new type of Covid, Ms Stephen-Smith said the ACT Government was not planning to start restricting interstate travel - but she didn't rule it out in future.

"At the moment, we are not considering changes to interstate travel into the ACT but obviously we monitor the situation in NSW very closely and every day," she said.

Most of Canberra's most recent COVID-19 cases have been linked to outbreaks in NSW and Victoria but ACT Health has said it's not considering any additional travel restrictions for now.

Across the weekend, the national capital recorded 36 additional cases. The rolling seven-day average has increased more than double to 12 from Tuesday when it averaged 5.

ACT Health has confirmed many of the recent cases are linked to strains circulating in other jurisdictions.

"A large proportion of the recent cases in the ACT were acquired from interstate," a spokesperson said in a statement on Sunday.

"Whole genome sequencing has indicated links to NSW and Victorian strains."

It comes as NSW recorded the largest daily number of infections in any Australian jurisdiction since the pandemic first began for a second day in a row.

The state recorded 2566 cases in the 24 hours to 8pm Saturday but no virus-related deaths.

Victoria also identified 1240 additional cases on Sunday.

The ACT prevented Canberrans from travelling to and from the Greater Sydney region in late June this year after the Bondi cluster grew beyond 50 cases.

Six weeks later, Canberra recorded its first local case in more than a year, resulting in a swift lockdown that lasted until October.

But while the bordering state is recording numbers higher than at the peak of the Delta outbreak, territory health authorities have insisted there are no plans to impose any travel restrictions for now.

"ACT Health strongly recommends all interstate travellers practise COVID safe behaviours including good hand hygiene, using masks indoors where physical distancing is difficult and staying home and getting tested if they develop symptoms," the spokesperson said.

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The news will be welcome for many hoping to reunite with families over the holiday period.

Qantas confirmed it had already seen a drop in activity due to the Omicron variant's arrival ahead of the usually busy period.

Overseas, the new variant has already wreaked havoc on the European holiday period with the Netherlands entering lockdown during Christmas and into 2022's first fortnight.

France announced it would cancel its New Year's Eve fireworks in Paris and will put additional restrictions on travellers entering from the United Kingdom, which has recorded a spike in Omicron cases.

Federal deputy chief medical officer Dr Sonya Bennett urged Australians on Sunday to continue wearing masks inside even if it wasn't mandated.

"I'd probably encourage everyone to think about continuing to wear masks, particularly in settings that are indoor, public indoor spaces that may not be well-ventilated," she said on Sunday morning.

"Think about wearing a mask. It's a simple, easy thing to do.

"We know at Christmas time the shops do get very crowded. I was there myself yesterday. It was really pleasing to see, you know, a large proportion of people still wearing masks. But probably not large enough.

"I will certainly be taking a mask to anywhere that's crowded, particularly around Christmas time, because it's an effective, another effective layer of protection."

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