Japan will ban the entry of all foreign visitors starting Tuesday, as omicron, the new variant of COVID-19, continues to spread around the world, Prime Minister Fumio Kishida announced Monday. 

The news comes after Japan announced over the weekend that anyone arriving from South Africa and eight other countries had to quarantine for 10 days at a government-designated facility.

Two cases of the new variant omicron have been confirmed in Ontario, Canada, government officials announced Sunday.

"Today, the province of Ontario has confirmed two cases of the Omicron variant of COVID-19 in Ottawa, both of which were reported in individuals with recent travel from Nigeria. Ottawa Public Health is conducting case and contact management and the patients are in isolation," Christine Elliott, deputy premier and minister of health, and Dr. Kieran Moore, chief medical officer of health, said in a statement.

South Africa's President Cyril Ramaphosa addressed his nation on Sunday following the detection of the omicron COVID variant and said the country's National Coronavirus Command Council met Saturday to consider the recent rise in infections and the possible impact of the omicron variant. They have decided not to impose further restrictions at this stage.

"We considered the fact that when we encountered previous waves of infection, vaccines were not widely available and far fewer people were vaccinated," Ramaphosa said.

Ramaphosa said they will closely monitor infection rates and hospitalization over the coming days and will review the situation in another week.

Only 23.66% of South Africa's population is fully vaccinated against COVID, according to the Africa CDC.

President Joe Biden, who is returning to the White House Sunday afternoon, will be briefed in person by his COVID-19 response team and Dr. Anthony Fauci for an update on the omicron variant.

This is Biden's third briefing on omicron since Friday.

"This afternoon, the president will have an in-person briefing with members of his COVID-19 response team and Chief Medical Advisor to the President Dr. Fauci to provide an update on the omicron variant and the administration’s response," a White House official told ABC News.

-ABC News' Justin Gomez

The symptoms from the omicron COVID-19 variant are mild, according to the South African doctor who spotted the variant.

"Looking at the mildness of the (omicron) symptoms that we are seeing, currently, there's no reason for panicking as we don't see severely ill patients," Dr. Angelique Coetzee, who is the Chair of the South African Medical Association, told Reuters. "The hype that's been created currently out there in the media and worldwide doesn't correlate with the clinical picture. And it doesn't warrant to just cut us off from any traveling and ban South Africa, as if we are the variants in the whole process, it should not be like that."

Coetzee said the most predominant complaints from those who have tested positive omicron are severe fatigue for a couple of days, as well as headaches and body aches.

-ABC News' Clark Bentson