The World Health Organization on Monday warned that the new Omicron variant has a “very high” global risk and urged national authorities to step up pandemic relief efforts.

WHO director-general Tedros Adhanom Ghebreyesus said at an assembly of health ministers that there is a continued need for testing and vaccinations given that recent findings labeled Omicron a "variant of concern."

“Omicron's very emergence is another reminder that although many of us might think we’re done with COVID-19, it’s not done with us,” he told a special session of the World Health Assembly that it is expected to launch negotiations on an international agreement on preventing future pandemics.

The new variant, which was first detected in South Africa last week, has a “high number of mutations,” meaning that “there could be future surges of COVID-19, which could have severe consequences.”

Though there have been no Omicron-linked deaths, it remains uncertain whether this variant presents a different severity profile and whether it could escape protection against immunity induced by vaccines and previous infections, the WHO said.

Omicron has now been detected in Australia, Belgium, Canada, Germany, Italy, the Netherlands, Portugal, the U.K. and other countries. It has also been detected in Israel and Hong Kong.

Even though there have been no reported Omicron cases in the U.S., White House chief medical adviser Dr. Anthony Fauci said the new variant could already have made it to the country. He added that it could be two weeks or longer before more information about the variant’s transmissibility, and the severity of illness it causes, is available, The New York Times noted.

Symptoms of the new Omicron COVID variant are said to be “extremely mild,” according to the South African doctor who first identified patients with the virus strain.

Scientists have cautioned that it is still unclear whether Omicron is more dangerous than other versions of a virus that has killed more than 5 million people worldwide, NBC News reported.

In response to the new variant, countries have been reimposing travel restrictions.

On Monday, Japan announced that it will be joining Israel in suspending entry to all foreign visitors.

The U.S. has restricted travel from South Africa and seven neighboring countries.

South Africa’s President Cyril Ramaphosa pushed back on those restrictions, highlighting injustices many developing countries have faced during the pandemic.

"We need to resist unjustified as well as unscientific travel restrictions that only serve to further disadvantage developing economies," Ramaphosa said Monday during a speech at the opening of the China-Africa Summit in Dakar.

While a large part of the global south is unvaccinated, many advanced economies have already been administering booster shots. With this, there has been a wide discrepancy in protection around the world.