BRUSSELS (AP) -- Nations around the world sought Monday to keep the new omicron variant at bay with travel bans and further restrictions, even as it remains unclear what it means for the COVID-19 pandemic.
Japan announced it would suspend entry of all foreign visitors, while new cases of the variant identified days ago by researchers in South Africa appeared as far apart as Hong Kong, Australia and Portugal. Portuguese authorities were investigating whether some of the infections there could be among the first reported cases of local transmission of the variant outside of southern Africa.
The stream of new cases showed the near impossibility of keeping the genie in the bottle in a globalized world of travel and open borders.
Yet, many tried to do just that, even against the urging of the World Health Organization, which noted that border closures often have limited effect but can wreak havoc on lives and livelihoods. Some argued that such restrictions still could provide valuable time to analyze the new variant. Little is known about it, including whether it is more contagious, more likely to cause serious illness or more able to evade the protection of vaccines.
While the initial global response to COVID-19 was criticized as slow and haphazard, the reaction to the new variant came quickly.
"This time the world showed it is learning," said EU Commission President Ursula von der Leyen, singling out South African President Cyril Ramaphosa for praise. "South Africa's analytic work and transparency and sharing its results was indispensable in allowing a swift global response. It no doubt saved many lives," she said.
The WHO has also praised South Africa and Botswana for quickly alerting the world to the presence of the new variant -- and many have warned they should not be punished for their speed, especially since it may never be known when or where the new version first cropped up.
But that did not hold von der Leyen back from pushing the 27-nation European Union toward imposing an immediate ban on flights from seven southern African nations -- similar to measures many countries have taken.
Cases had already been reported in Belgium, Denmark and the Netherlands, before Portuguese authorities identified 13 cases of omicron among team members of the Belenenses professional soccer club. Authorities reported that one member recently traveled to South Africa. Its game against Benfica over the weekend had be abandoned at half time for lack of players.
Quarantining also became an issue when Dutch military police had to arrest a husband and wife who left a hotel where they were being held after testing positive and boarded a plane bound for Spain.
"Quarantine is not obligatory, but we assume people will act responsibly," spokeswoman Petra Faber said.
Taking no chances, Japan, which has yet to detect any omicron cases, reimposed border controls that it eased earlier this month for short-term business visitors, foreign students and workers.
"We are taking the step as an emergency precaution to prevent a worst-case scenario in Japan," Prime Minister Fumio Kishida said of the measure that begins Tuesday. Japan has kept its border closed to foreign tourists from all nations.
Israel decided to bar entry to foreigners, and Morocco said it would suspend all incoming flights for two weeks starting Monday.
Despite the global worry, scientists cautioned that it's still unclear whether omicron is more alarming than other versions of a virus that has killed more than 5 million people. And in some parts of the world, authorities were moving in the opposite direction.
In Malaysia, officials went ahead with the partial reopening of a bridge connecting it to the city-state of Singapore. And New Zealand announced it will continue plans to reopen internally after months of shutdown, though it is also restricting travel from nine southern African nations.
Prime Minister Jacinda Ardern said she didn't anticipate any further restrictions, and bars, restaurants and gyms in Auckland can reopen from late Thursday, ending a coronavirus lockdown that began in August.
"We've come through the past two years of COVID in better shape than nearly anywhere in the world," Ardern said, pointing to low death rates, a growing economy and high vaccination rates.
Dr. Francis Collins, director of the National Institutes of Health in the United States, meanwhile, said no data as yet suggest the new variant causes more serious illness than previous COVID-19 variants.
Collins echoed several experts in saying the news should make everyone redouble their efforts to use the tools the world already has, including vaccinations, booster shots and measures such as mask-wearing.
The U.S. is banning travel from South Africa and seven other southern African countries starting Monday. "It's going to give us a period of time to enhance our preparedness," the United States' top infectious diseases expert, Dr. Anthony Fauci, said of the ban on ABC's "This Week."
Fauci says it will take approximately two more weeks to have more definitive information on the transmissibility, severity and other characteristics of omicron, according to a statement from the White House.