Two cases of Omicron were confirmed in Canada on Sunday - both in patients in the capital, Ottawa, who had traveled to Nigeria. Nigeria is not on the list of countries affected by Biden's travel ban, announced on Friday.
Further updates on those patients' conditions have not been shared.

The White House on Sunday called on people to get their booster shots as a matter of urgency, as the new variant Omicron was confirmed to have arrived in North America.

Joe Biden returned from his Thanksgiving break to hold an emergency meeting with his COVID advisors on Sunday evening - with Dr Anthony Fauci sounding a hopeful note, saying he believed 'existing vaccines are likely to provide a degree of protection against severe cases' from Omicron.

Upon returning from Massachusetts, Biden was asked whether he was considering additional travel restrictions.

'I'm having a meeting with my medical team as I get back to the White House. I'll have more to say,' he said.

The White House then issued a photo of Biden sitting in the Oval Office with Fauci, his chief medical advisor; his chief of staff, Ron Klain; Jeff Zients, White House Coronavirus Response Coordinator; and two others.

Following up on the regular briefings he had on COVID while traveling, the President met in person today with his Chief Medical Advisor, Dr. Anthony Fauci, and members of his White House COVID Response Team on the latest developments related to the Omicron variant,' the White House said.

'Dr. Fauci informed @POTUS that while it will take approximately two more weeks to have more definitive information on the transmissibility, severity, and other characteristics of the variant, existing vaccines are likely to provide a degree of protection against severe cases.

'Dr. Fauci also reiterated that boosters for fully vaccinated individuals provide the strongest available protection from COVID. The COVID Response Team's immediate recommendation to all vaccinated adults is to get a booster shot as soon as possible.'

Yet despite the White House's concern, there are no new rules on testing before or after travel.

Airline passengers entering the United States from abroad must prove that they are vaccinated before they board, but are not generally monitored by health officials after they leave flights and are not required to take a COVID-19 test upon arrival in the United States.

Americans do not need to be vaccinated to return home, but they must usually provide a negative COVID test, taken no more than 72 hours before, to fly.

Americans can still fly from the 'banned' countries.

Ottawa Public Health is conducting case and contact management and the patients are in isolation.'

Canada, like the U.S., has banned travel from South Africa - which has the largest number of cases - and seven regional countries.

But Nigeria is not one of the countries on the banned list.

Eric Feigel-Ding, an epidemiologist, told DailyMail.com on Friday that he believed the new variant was 'probably worldwide' already.

A patient in Belgium who tested positive - the first in Europe - had not been in sub Saharan Africa. She had traveled to Egypt via Turkey, and tested positive for Omicron on her return.

'The best defense against the omicron variant is stopping it at our border,' said Elliott and Moore.

'In addition to the measures recently announced, we continue to urge the federal government to take the necessary steps to mandate point-of-arrival testing for all travelers irrespective of where they're coming from to further protect against the spread of this new variant.'

The provincial government urged residents to get vaccinated, including with booster doses, and to continue following public health guidance.

'Ontario is prepared and ready to respond to this new variant.'

Canada's health minister said that the swift-identification of the variant showed that their testing system was working.

'As the monitoring and testing continues with provinces and territories, it is expected that other cases of this variant will be found in Canada,' said Jean-Yves Duclos.