Guernsey's schools, colleges and pre-schools will close from Monday until at least after the Easter holidays.
The island's director of public health said it was not possible to assess the spread of the virus there because test results in the UK have been delayed.
The closures aim to limit the spread of the virus until local testing begins.
The equipment needed to begin testing has been ordered and a facility could be ready before the end of the Easter holidays.
One person so far has tested positive in the island, with 149 people returning negative results and 78 tests outstanding.
The patient is in self-isolation with their family since returning from Tenerife.
Dr Nicola Brink, director of public health, said: "When Guernsey is able to carry out its own testing, work will be done to quickly determine the extent to which 'community seeding' is taking place - in other words, how much coronavirus spreads from one person in the Bailiwick to another, as opposed to cases coming into the island from other jurisdictions.
"The travel restrictions which have come into effect today, where people who arrive in the Bailiwick by law have to self-isolate for 14 days, and the guidance on social distancing and other ways of reducing contact mean there is a reasonable chance that the Bailiwick will be able to remain in the 'containment' phase and schools can resume as soon as possible after the scheduled Easter break.
"However, it is possible that if the data shows community seeding is occurring, a decision will have to be made to keep schools closed."
The States said childcare would be provided for the children of key workers and children with special educational needs and details would be announced on Friday.