One billion people could become infected with the coronavirus worldwide unless vulnerable countries are given urgent help, an aid group has warned.

The International Rescue Committee (IRC) said financial and humanitarian aid were needed to help slow the global spread of the virus.

It said “fragile countries” such as Afghanistan and Syria needed “urgent funding” to avoid a major outbreak.

“There remains a small window of time to mount a robust response,” it warned.

There have been more than three million confirmed cases of Covid-19 worldwide with more than 211,000 deaths, according to Johns Hopkins University in the US.

Italy, Spain, France and the UK accounted for more than 21,000 virus-related deaths each.

The IRC’s report, which is based on models and data from the World Health Organisation (WHO) and Imperial College London, estimated there could be between 500 million and one billion infections globally.

It also said there could be more than three million deaths across dozens of conflict-affected and unstable countries.

“These numbers should serve as a wake-up call,” said the head of the IRC, David Miliband.

“The full, devastating and disproportionate weight of this pandemic has yet to be felt in the world’s most fragile and war-torn countries,” he added.

“The key now is for donors to urgently put flexible funding behind frontline efforts.

“Governments must work together to remove any impediment to humanitarian assistance.”

The US-based group, which responds to humanitarian crises around the world, said factors such as household size, population density, healthcare capacity and pre-existing conflicts could all increase the risk of major outbreaks developing.

Many countries in the developing world have low official infection rates or death tolls, but the actual numbers are believed to be much higher.

New Zealand has eased a strict lockdown amid hopeful signs coronavirus has been all but vanquished in Australasia for the moment.

But fresh doubts have been raised over whether Japan would be able to host the already postponed Olympic Games next year.

Europe and some US states are also continuing to gradually ease limits on movement and commerce as they try to restart their economies.

But in a reminder of the virus’s increasing toll, President Donald Trump said the numbers of deaths could reach 70,000 in the US, after putting the number at 60,000 several times earlier this month.

With the number of new cases waning, New Zealand’s government loosened its lockdown, which for more than a month had closed schools and most businesses, and only allowed people to leave their homes for essential work, to get groceries or to exercise.

Most students will continue studying from home and workers are still required to work from home if they can, while everyone is required to maintain social distancing.

But restaurants can now reopen for takeaway orders, construction can restart, and golfers and surfers can play.

New Zealand reported just three new infections on Tuesday and the country’s health authorities said they are winning the battle against the virus.

Nevertheless, they cautioned people not to get complacent and to maintain social distancing.

Prime Minister Jacinda Ardern said people had done an incredible job to break the chain of transmission, but cautioned they needed to remain vigilant.

Quoting a microbiologist, Ms Ardern said “there may still be some smouldering ashes out there, and they have the potential to become a wildfire again, if we give them the chance.”

In Australia, authorities have reopened Sydney’s Bondi Beach to swimmers and surfers and hundreds returned to the water as soon as the restrictions were lifted.

People can only use the beach during daylight hours. cannot linger on the sand and are counted to ensure social distancing.

In France, President Emmanuel Macron wants schools to start reopening May 11, but teachers, parents and even some mayors are raising alarms.

The government says it will be up to parents to decide whether to send children back to class, with details expected later on Tuesday.

Greece, which has managed to keep its coronavirus death toll low, at 136 people, is also releasing more lockdown easing details on Tuesday but the issue of schools remains tricky.

Schools will be reopened “gradually, with conditions” and subject to constant review, said the Health Ministry’s virus spokesman, infectious diseases specialist Sotiris Tsiodras.

The team of experts he is on has not recommended a date.

In Japan, a top medical expert said he thinks it will be difficult to hold the Olympics in 2021 without an effective coronavirus vaccine.

Japan and the International Olympic Committee agreed to postpone the Tokyo 2020 Games until July next year due to the pandemic. 

Japan is under a month-long state of emergency amid a rapid increase of infections throughout the country, where hospitals are overburdened.

“I hope vaccines and drugs will be developed as soon as possible,” said Yoshitake Yokokura, the president of the Japan Medical Association.