The World Health Organization warned that blanket travel bans won't prevent the spread of Omicron, as more countries rushed to impose curbs and there were first cases of the new Covid strain in Latin America.
In the week since the new virus strain was reported by South Africa, dozens of countries around the world have responded with travel restrictions - most of them targeting southern African nations.
A World Health Organization warned that blanket travel bans could cause more harm than good, just as Canada expanded its restrictions.
In a travel advisory, the WHO warned that the bans could dissuade countries from sharing data about the evolving virus.
But it did advise that people who are vulnerable to Covid 19, including over 60 s, should not travel to areas with community transmission of the disease.
WHO chief Tedros Adhanom Ghebreyesus said it was understandable for countries to try to protect their citizens against a variant we don't yet understand but he also called for the global response to be calm, coordinated and coherent urging nations to take rational travel restrictions when Dutch authorities reported that Omicron was present in the country before South Africa reported its first cases on November 25.
The new variant, whose high number of mutations the WHO believes may make it more transmissible or resistant to vaccines - was found in two Dutch test samples from November 19 and 23, with one having no travel history.
There are well over a dozen countries and territories that have detected cases, including Australia, Britain, Canada, Hong Kong, Israel, Italy and Portugal.
Latin America reported its first two cases Tuesday -- in people who travelled from South Africa to Brazil -- and a first case was confirmed in Japan -- a day after it barred all foreign arrivals.
US President Joe Biden said that the travel bans on just the southern African nations would stay in place, without reference to the other places where Omicron has been detected.
Biden said that it depends on how long travel restrictions will take effect on South Africa and seven other southern African countries, and that we're going to learn a lot more in the next couple weeks about the lethality of this disease, how much we have to control it, etc., etc.
Asked if travel restrictions could be extended suddenly to other countries, as happened under Trump, Biden said: Unlike Trump, I don't shock our allies. In Asia, governments continued to expand restrictions, including Indonesia adding Hong Kong to its travel ban list, along with various African nations.
Hong Kong added three more countries - Japan, Portugal and Sweden -- to its highest travel restriction category after Omicron cases were discovered in those nations.
While much is still unknown about the Omicron variant, it could take weeks to determine whether and to what extent it is vaccine resistant -- it has highlighted that the global fight against Covid 19 is far from over.
Omicron has emerged as much of the northern hemisphere was already bracing for a new winter wave of the pandemic - leaving even nations with high vaccination rates struggling to contain rising infection numbers and prevent health services from being overwhelmed.
Governments in Western Europe have already reintroduced mandatory mask-wearing, social-distancing measures, curfews or lockdowns, leaving businesses fearing another grim Christmas.
Greece went ahead Tuesday in making vaccine compulsory for over 60 s, while Norway will offer booster shots to all adults before Easter, as preferring a lockdown.
Britain has a target of delivering third jabs to all adults within two months.
While the European summer of fleeting Covid freedoms may be over, the Pacific island of Fiji ended its 615 days of international isolation on Wednesday and was reopened to tourists in the southern hemisphere.
Traditional dancers in grass skirts welcomed holidaymakers from Sydney, the first of an expected flood of tourists in the coming weeks.
He told reporters that the international border reopening will reignite Fiji's economy.