British Prime Minister Boris Johnson says tougher restrictions may be necessary in his country, where a variant of the coronavirus is rapidly spreading.
He spoke to the BBC on Sunday as the United Kingdom confirmed more than 50,000 new cases for the sixth day in a row, with 54,990 reported on the day.
Restrictions on people's outings and orders to close almost all non-essential shops are already in place in southeastern England, including London.
Johnson said, "It may be that we need to do things in the next few weeks that will be tougher in many parts of the country."
He suggested the possibility of keeping schools closed. That would run counter to his plans for primary schools to reopen in most of England on Monday amid opposition from teachers' unions.
Reopening of primary schools has already been postponed in London and some other badly affected areas.
Johnson expressed his hope that the situation will improve by the spring, as more people are vaccinated.
He said the government hopes tens of millions of people will be able to receive the vaccines in the next three months.
A new vaccine developed by British pharmaceutical firm AstraZeneca and the University of Oxford is scheduled to be given from Monday.