Children worldwide have lost more than a third of the standard global 190-day school year because of the coronavirus pandemic, Save the Children said Tuesday following a wide-ranging research review.

The London-based charity urged governments and donors to take swift action to prevent "an irreversible impact" on the lives of millions of children who now may never return to school.

It analysed data compiled primarily by UNESCO, the UN educational and cultural organisation, and UNICEF, the UN body dedicated to children.

The figures showed that children have missed 74 days of education on average due to school closures caused by the global health crisis, and a lack of access to remote learning.

Using the UN agencies' statistics and data from the US-based Center for Global Development, the charity calculated that 112 billion school days had been lost in total -- and the poorest were disproportionately affected.

Children in Latin America, the Caribbean and South Asia missed out on almost triple the education of those in Western Europe, it added.

"Almost a year after the global pandemic was officially declared, hundreds of millions of children remain out of school," said chief executive Inger Ashing.

"2021 must be the year to ensure that children do not pay the price for this pandemic.

"We will lose the war against the pandemic if we do not ensure children get back to school safely, have access to health services, have enough to eat and are protected."

Supporting children's safe return to school should be made a priority at this year's meeting of G7 wealthy nations, hosted by Britain in June, said the charity.

While some countries, such as Colombia, have reopened schools children around the world have lost out during the pandemic
While some countries, such as Colombia, have reopened schools children around the world have lost out during the pandemic AFP / Luis ROBAYO

That call was echoed by a spokeswoman for UNESCO.

"We need a substantial stimulus package to reopen schools safely, targeting the poorest and getting education back on track for the Covid-19 generation," she told AFP.

Save the Children's review of UNESCO's research found at the peak of the pandemic last year, 91 percent of the world's learners were locked out of schools.

The restrictions have widened the wealth and opportunity gap both between and within countries, it concluded.

"The divide grew between wealthier and poorer families; urban and rural households; refugees or displaced children and host populations; children with disabilities and children without disabilities," Save the Children added.

It interviewed Santiago, a 13-year-old Venezuelan who attends a school for children with a profound hearing loss supported by the charity. He reported being "sad, worried, and scared" by the situation.

"I like school. People understand me there. When I can't go to school, I cry and just want to sleep," he was quoted as saying.

Save the Children also paired UNICEF research with data from the European Union and US Census Bureau to discover "huge discrepancies" in access to remote learning in wealthier nations.

Students in the United States are more disconnected from the internet than those in other high-income countries, likely hindering their online learning, it said.

Meanwhile in Norway, 30 percent of youths aged nine to 18 did not have access to a computer at home, and in the Netherlands this was one of five children.

Coronavirus