Parents should send their children to primary school on Monday as long as they are open in their area, Boris Johnson has said.
The British PM said there was "no doubt in my mind that schools are safe".
The two-week school closures in London and the South East of England were "exceptional" due to a fast-spreading new variant of Covid-19, he said.
But the prime minister did not rule out further school closures and indicated tougher measures could be introduced.
Johnson told the BBC's Andrew Marr Show the risk to children was "very, very low" and the benefit of education was "so huge".
Most primary schools in England, except those in London and parts of the South East, are expected to open on Monday.
However, unions are telling primary school staff it is unsafe to return to work and are calling for remote learning to be introduced across all primary schools.
Some local authorities have also expressed concerns about reopening schools after the Christmas break.
Johnson said that while school closures would be kept "under constant review", the government would be "driven by public health considerations and by the massive importance of education".
"And if you think about the history of the pandemic, we've kept schools going for a long, long time in areas where the pandemic has really been at really high levels," he said.
On Friday, Education Secretary Gavin Williamson announced that all of London's primaries would remain shut to most pupils, after pressure from local councils to reverse an earlier decision to keep only schools in certain boroughs closed.
(Source: BBC)
