- It comes shortly after Wales, Northern Ireland and Scotland announced their schools would close from Friday.
- All schools and colleges in the Republic of Ireland have also been closed.
- "This does mean that exams will not take place as planned in May and June, though we will make sure that pupils get the qualifications they need and deserve for their academic career," Johnson said.
The U.K. government said Wednesday it plans to shut schools in England as a result of the coronavirus pandemic.
Speaking at the government's daily press conference on the coronavirus outbreak, Prime Minister Boris Johnson said: "Looking at where we are now, we think now that we must apply further downward pressure on that upward curve by closing the schools."
"So, I can announce today … that after schools shut their gates from Friday afternoon, they will remain closed for the vast majority of pupils until further notice."
It comes shortly after Wales, Northern Ireland and Scotland announced their schools would close from Friday. All schools and colleges in the Republic of Ireland have also been closed.
"This does mean that exams will not take place as planned in May and June, though we will make sure that pupils get the qualifications they need and deserve for their academic career," Johnson said.
As of Wednesday, the U.K. had more than 2,600 confirmed cases of COVID-19, with 72 deaths, according to Johns Hopkins University data.
On Tuesday, the U.K.'s finance minister announced a £330 billion ($398 billion) aid package of loans for businesses, as well as a business rates holiday and grants.
Finance Minister Rishi Sunak said the government would "support jobs ... support incomes and we will support businesses ... we will do whatever it takes," he said.
"That means any businesses that needs access to cash ... will be able to access a government-backed loan," he said. Sunak noted that the scale of government interventions in the economy were "unimaginable" just weeks ago.
The U.K. government has been accused of being too cautious with their approach to the outbreak.
When asked why the government had decided not to impose lockdown measures for the city of London, as some had expected, Johnson replied: "We have always said that we are going to do the right measures at the right time."
On Wednesday, Wales and Scotland announced that their schools would close at the end of the week, putting pressure on the government in London to follow suit. Those in Scotland might stay closed until the summer break, Scotland's First Minister Nicola Sturgeon said.
Schools in England are already under pressure due to staff shortages caused by the virus.
On Monday, Johnson stepped up the U.K.'s advice to citizens, telling them to avoid all unnecessary social contact and to stop going to restaurants, clubs, pubs and theaters.
Sterling slid to $1.1459 on Wednesday to hit its lowest point since October 2016 as liquidity concerns sent the dollar surging and hammered currencies around the world.
The pound fell more than 4% on the session to hit its lowest point since 1985, with the exception of an overnight "flash crash" in October 2016 which took sterling to $1.1450.