Schools across Northern Ireland are to shut from Monday in response to the coronavirus pandemic.
First Minister Arlene Foster, alongside deputy First Minister Michelle O'Neill, made the announcement on Wednesday evening and said the closures would "likely" continue beyond the summer holidays.
Meanwhile, Prime Minister Boris Johnson confirmed that schools in England would close from Friday and that GCSE and A-Level examinations were cancelled.
This came just hours after both Scotland and Wales made the same decision to close their schools.
In the Republic of Ireland schools have been closed since last Friday.
Mrs O'Neill also said that a £370m support package for Northern Ireland businesses was being made available to support the most vulnerable companies.
The news on school closures came as:
Speaking at Stormont Castle, Mrs Foster said that the decision to close Northern Ireland's schools was "unprecedented".
"Our school principals, parents and pupils have been in a holding pattern based on medical advice for the last week," stated the DUP leader.
"Today we have agreed that all schools will close from Monday, March 23.
"The societal and economic impact of this measure will be enormous as parents have to adjust their routine to deal with this unplanned, long-term closure.
"Our medical advice was to delay this step for as long as possible as the closure will likely take us beyond the natural break for summer."
She added that children's education cannot cease and that the Executive is exploring how schools can continue to be a "base" for those whose parents work in the health service.
In his address to the nation, the Prime Minister said that all GCSE and A-Level exams in May and June have been cancelled because of coronavirus.
Commenting on school exams, Mrs Foster explained that the Executive is currently speaking to exam bodies and as soon as a "clear answer" is received, it will be made public.
Mr Johnson said the Government would ensure that "in time" pupils due to sit exams this summer get the qualifications they need. According to the Prime Minister, qualifications would be "administered" fairly and in order to protect pupils' interests but he did not give details on how and when that would happen.
He also urged parents not to leave children in the care of grandparents or older relatives who are at higher risk of becoming seriously ill with coronavirus, after announcing that schools, nurseries and colleges would close.
Releasing details of Stormont's plan to help Northern Ireland's businesses, Mrs O'Neill stated that "it cannot be business as usual".
An immediate grant of £10,000 will be provided to all small businesses who are eligible for the small business rate relief scheme - costing £267m and assisting some 27,000 businesses.
Companies in the retail, tourism and hospitality sectors will also be eligible for an immediate grant of £25,000.
It is estimated that will cost £100m and will help around 4,000 businesses.
The schemes will be administered by the Department for Economy and Invest NI, working in partnership with the Department of Finance's Land and Property Services.
Sinn Fein's deputy leader also said that further announcements will be made in the coming days.
"As a power-sharing government, know that we are absolutely united on your behalf," said Mrs O'Neill.
"That is what you all deserve.
"That is what we as ministers are 100% committed to delivering.
"Your health and wellbeing is paramount.
"We are pledging, to you all, that the sole focus of government has now turned to doing everything that is necessary to secure our public services, and to ensure that our employers, workers and their families are supported.
"Our power-sharing government is determined to ensure that we act swiftly and decisively in your interests.
"Acting together and standing together, government with community, I know we will come through this."
She added that Stormont will also launch a communities response plan, a community support fund and an enhanced discretionary support fund, as well as exploring support for people on the private and social rental sectors, and support for people in crisis and emergency accommodation.
From behind the front window of her home, about half a mile from the Co Londonderry village of Bellaghy, Marietta Duffin gazes out onto a scene of rolling countryside basking in early spring sunshine.