Schools, colleges and other public facilities in the Republic of Ireland are to close in the wake of the coronavirus outbreak.
Taoiseach (Irish prime minister) Leo Varadkar said the measures would take effect from 18:00 on Thursday to 29 March.
He said indoor mass gatherings of more than 100 people and outdoor gatherings of more than 500 should be cancelled.
He added that where it is possible to work remotely people should do so.
The first death linked to coronavirus has been recorded in the Republic of Ireland.
The elderly woman died in a Dublin hospital on Wednesday.
Mr Varadkar said schools, colleges and childcare facilities will close from Friday.
He added the public and businesses needed to take a sensible approach, adding that the Irish cabinet would meet later and that Northern Ireland and GB would be briefed.
“I know that some of this is coming as a real shock and it is going to involve big changes in the way we live our lives and I know I’m asking people to make enormous sacrifices but we’re doing it for each other,” Mr Varadkar said.
“Our economy will suffer but it will bounce back.
“Lost time in school or college will be recovered and in time our lives will go back to normal.
“Ireland is a great nation, we’re great people, we’ve experienced hardship and struggle before, we’ve overcome many trials in the past.”
Mr Varadkar said shops should remain open and public transport will continue to operate.
‘Necessary and justified’
He said the government would implement all resources, which are “substantial but not unlimited”, into addressing the issue.
Later, Tánaiste (Irish deputy prime minister) Simon Coveney said the closures ” will disrupt everyday activity – everyday activity that makes us who we are”.
“The actions we are announcing today are absolutely necessary and justified,” he added.
“We are asking people to continue to work.
“Those who go to their places of work should limit their contacts, particularly face-to-face meetings.
“We do need to respond with calm, with unity, with discipline and resolve.
“These are the right measures at the right time based on the best public health advice.”
Irish health minister Simon Harris said all museums, galleries and tourist sites will also be closed.
He urged older people in particular to reduce their social contacts outside the home.