Nearly 300 million children across the globe are not in school as a result of the spread of coronavirus.
While most cases and deaths of Covid-19 are in China, the spread to nearly every continent on Earth has seen some 290 million students across 13 countries kept out of the classroom as schools implemented closures, according to UNESCO.
UNESCO chief Audrey Azoulay said: "The global scale and speed of the current educational disruption is unparalleled and, if prolonged, could threaten the right to education.”
South Korea, where cases of coronavirus have hit nearly 6,000, has delayed the start of the school term until 23 March, while on Wednesday Italy ordered all schools and universities to be shut until 15 March.
Japanese prime minister Shinzo Abe also called for all classes in the country to be cancelled throughout March and into early April.
While the UK Government has not yet advised any school closures as a result of 90 people in the country testing positive for the illness, some universities have postponed their graduation ceremonies.
Buckingham University and the University of London said they had taken a "difficult" decision to call off ceremonies this month to minimise the risks to students and their guests from Covid-19.
The University of London said it had expected up to 4,000 people from more than 100 countries - including international students with friends and family - to have attended its March 3 ceremony at the Barbican Centre.
It came as Goldsmiths University in south London said a visitor to one of the university's halls of residences had tested positive for the virus.
The ceremony cancellations covered students' distance and flexible learning programmes.
Pro vice-chancellor Chris Cobb said: "We have taken the difficult decision to postpone the event due to the ongoing coronavirus issue.
"We truly regret the inconvenience caused but, after careful consideration, we felt it important to minimise the risk to our students and their guests.
"This event is different to many others due to the large numbers of attendees travelling from affected regions and the potential impact it may have on others attending and travelling back to regions which are currently unaffected.”
Buckingham University vice-chancellor Sir Anthony Seldon said postponing the March 21-22 ceremonies was a precautionary measure, and the aim is to hold the event on campus in Buckingham later in the year.
Health Secretary Matt Hancock told BBC Breakfast on Tuesday: "What we can say for sure is that, right now, we do not recommend the cancelling of mass events, and schools as well should not be closing unless there is both a positive case and the school has had the advice to close from Public Health England.”
The Department for Education said PHE has issued guidance to help schools and other academic institutions give advice to pupils, students, staff, parents or carers.