Omicron variant poses 'very high' global risk as Dutch police arrest couple boarding plane after fleeing quarantine while Japan bans foreigners and Australia scraps reopening borders

Japan will ban all foreigners from entering the country starting at midnight on Monday, with citizens returning from nations deemed 'high risk' forced into quarantine (pictured, a man at Tokyo airport)

WHO director Dr Tedros Ghebreyesus (pictured) called for a global treaty on how to deal with future pandemics as the health body warned Omicron poses a 'very high' risk to the global Covid recover

Omicron, which was first identified in South Africa but is thought to have originated in Botswana, is the most-mutated form of Covid yet found and has been declared a 'variant of concern' by the WHO because early data suggests it is more-infectious than the Delta strain and may have an increased ability to infect vaccinated people.

But data is limited to just a few dozen cases and huge question marks remain, including whether Omicron causes more serious disease as well as being more infectious. Dr Angelique Coetzee, the South African doctor who treated the first known cases, has said that so-far the symptoms seem milder than the Delta variant. 

The most-common symptoms of Omicron are extreme fatigue, increased heart-rate and a scratchy throat, she said. None of the patients she has treated for the variant have become sick enough to require hospital treatment.

Britain, the current head of the G7 presidency, has called a meeting of health ministers due to take place today to discuss the potential problems that Omicron poses. 

Speaking virtually at a separate summit in Geneva today, Dr Tedros warned that the world 'remains in the grip of pestilence' and that more action is needed globally to eradicate Covid.

'We shouldn't need another wake-up call,' he told delegates. 'We should all be wide awake to the threat of this virus. But Omicron's emergence is another reminder that although many of us might think we're done with Covid-19, it is not done with us.'

He again repeated calls for vaccines to be shared with poorer countries, saying leaders should make it their target to vaccinate 50 per cent of the global population before the end of the year and 70 per cent of the population by mid-2022.

'Nobody is safe, until everybody is safe,' he added. 

Dr Tedros also spoke out against travel bans to stem the spread of Covid, saying they are ineffective in the long-run and unfairly punish nations for disclosing the existence of new diseases and mutations. 

Nevertheless, governments have taken steps to tighten their borders as cases of the Omicron variant of coronavirus appeared in countries on opposite sides of the world.

Japan was the latest to take action as it said it would suspend the entry of all foreign visitors from around the world as the variant spreads.

'We are taking the step as an emergency precaution to prevent a worst-case scenario in Japan,' said Prime Minister Fumio Kishida. He said the measure will take effect on Tuesday.

The decision means Japan will restore border controls that it eased earlier this month for short-term business visitors, foreign students and workers.

Mr Kishida urged people to continue with mask wearing and other basic anti-virus measures until further details of the new Omicron variant are known.

Many countries have moved to tighten their borders even as scientists warned that it is not clear if the new variant is more alarming than other versions of the virus.

The variant was identified days ago by researchers in South Africa, and much is still not known about it, including whether it is more contagious, more likely to cause serious illness or more able to evade the protection of vaccines.

But many countries rushed to act, reflecting anxiety about anything that could prolong the pandemic that has killed more than five million people.

Australian authorities announced that they would delay plans to relax border restrictions by at least two weeks, until December 15, as the country reported its fifth case of the Omicron variant.

New South Wales state authorities reported on Sunday that two travellers from South Africa to Sydney had become Australia's first cases of the new variant. Both were fully vaccinated, showed no symptoms and were in quarantine in Sydney.

On Monday, another two cases were confirmed in Sydney after arriving in Australia's most populous state on a flight from southern Africa on Sunday, the state government said.

A South African man in his 30s who flew from Johannesburg to the northern Australian city of Darwin last Thursday also tested positive for the Omicron variant, officials said.

'The temporary pause will ensure Australia can gather the information we need to better understand the Omicron variant, including the efficacy of the vaccine, the range of illness, including if it may generate more mild symptoms, and the level of transmission,' a government statement said.

New South Wales and Victoria, as well as the national capital, Canberra, have introduced a blanket 72-hour quarantine requirement for all international arrivals.

Israel decided to bar entry to foreigners, and Morocco said it would suspend all incoming flights for two weeks starting on Monday - among the most drastic of a growing raft of travel curbs being imposed by nations around the world as they scrambled to slow the variant's spread

Scientists in several places - from Hong Kong to Europe to North America - have confirmed its presence. The Netherlands reported 13 Omicron cases on Sunday, and Canada has found two.

Noting that the variant has already been detected in many countries and that closing borders often has limited effect, the World Health Organisation (WHO) called for frontiers to remain open.

Dr Francis Collins, director of the National Institutes of Health in the United States, meanwhile, emphasised that there is no data yet that suggests the new variant causes more serious illness than previous Covid-19 variants.

'I do think it's more contagious when you look at how rapidly it spread through multiple districts in South Africa. It has the earmarks therefore of being particularly likely to spread from one person to another. What we don't know is whether it can compete with Delta,' said Dr Collins.

Dr 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.

'I know, America, you're really tired about hearing those things, but the virus is not tired of us,' Dr Collins said.

The Dutch public health authority confirmed that 13 people who arrived from South Africa on Friday have so far tested positive for Omicron.

They were among 61 people who tested positive for the virus after arriving on the last two flights to Amsterdam's Schiphol Airport before a flight ban was implemented. They were immediately put into isolation, most at a nearby hotel.

On Sunday, Dutch military police arrested a husband and wife who had left the hotel where they were being quarantined and had boarded a plane at Schiphol Airport.

Local media reported that the couple were trying to fly home to Spain.

A spokeswoman for the local security authority said on Monday that an investigation was under way into whether the couple had committed a crime and should be prosecuted.

Portugal has confirmed 13 cases of the new Omicron Covid variant, all linked to Lisbon football team Belenenses who were forced to play a game against Benfica on Saturday with just nine men (pictured) because the rest were in isolation