Ireland has announced the closure of all schools and colleges, and advised the cancelation of mass gatherings as part of measures to combat the spread of COVID-19. 

Prime Minister Leo Varadkar said "schools, colleges and childcare facilities will close from tomorrow [Friday]," in addition to cultural institutions. 

Indoor events hosting more than 100 people and those outdoor involving more than 500 "should be cancelled," said Varadkar in a statement while on an official visit in Washington DC, U.S.

Ireland currently has 43 confirmed cases of the coronavirus and announced on Wednesday the first official death in the country. Varadkar also warned that more cases and deaths were expected as the world moved into what he described as "uncharted territory."

The measures were described as being part of the government's "duty to protect" the public and the restrictions are being put in place until 29 March.

Varadkar said people could still go to work because public transport was not affected, but the prime minister recommended home-working, staggered working and break times wherever possible in order to minimize contact between people and encourage social distancing. 

The new guidance comes after a meeting between the Varadkar and the government's National Public Health Emergency Team on Wednesday night. 

In Dublin, foreign minister Simon Coveney said to a news conference: "This is a phase that we have been planning for some time." He added that they are "the right measures at the right time" and were based on best public health advice. 

Varadkar said: "In order to pull together as a country, now we are asking people to stay apart." 

Ireland's chief medical officer, Tony Holohan, said there had been a "significant increase" in the number of cases detected in recent days, and urged people to be socially distant. 

Annual St Patrick's Day parades have been canceled in Ireland, which normally attract hundreds of thousands of people, in order to prevent the spread of COVID-19. Similar parades in Boston and New York have also been canceled.