Contact tracing is set to be rolled out in Wales from next week, according to the Welsh Government.
Health Minister Vaughan Gething said they will start phasing in contact tracing from 1 June as ministers hope it will help them ease Wales out of lockdown.
Contact tracing means testing people for coronavirus, tracking the spread of the virus, then tracing the people an infected person has come into contact with.
People who have come into close contact with someone who has tested positive for coronavirus will then be asked to self-isolate.
This includes people in the same household, those who have been within one metre, or who have been within two metres for 15 minutes or more.
The Welsh Government also announced it would be extending testing to under-5s in Wales, calling it an "important step to help ensure that all children can return to their education or childcare settings safely."
There have been contact tracing pilots running in Hywel Dda, Powys, Betsi Cadwaladr and Cwum Taf Morgannwg health board areas since 18 May.
The health minister said the Welsh Government's Test, Trace, Protect Strategy will be a "key enabler" when Wales seeks to ease lockdown restrictions.
Work is still continuing on the new NHS Covid-19 app before it can be launched across the rest of the UK.
Following its rollout on the Isle of Wight, more than 52,000 people on the island downloaded the app in the first week.
The app will form part of the NHS Test and Trace service and “is due to be launched in the coming weeks once contact tracing is up and running”.
A test-and-trace operation is setto be implemented in England on Thursday.