Norway, one of the first European countries to begin lifting confinement measures, is launching a smartphone tracking and tracing app to try to halt a return of the deadly coronavirus.

The "Smittestop" or "stop infection" app has been developed in the Nordic country to provide health authorities a better picture of the spread of COVID-19 and tell users if they have been in contact with the disease.

"To get back to a more normal life and keep the virus under control, we all have to make an effort and use this application," said Prime Minister Erna Solberg.

"If we fail to keep control (over the epidemic), we will have to tighten up again," she told a press conference on Thursday.

Use of the app is not mandatory and is free.

Users will be notified if were in close proximity to (less than two metres) someone infected with the coronavirus for more than 15 minutes, but does identify that person.

A user's movements will be registered with geo-localisation to enable authorities to gauge the effectiveness of easing restrictions and ultimately if new measures are required.

Despite concerns over privacy, data collection has been centralised but users will remain anonymous and their information destroyed automatically after 30 days.

Health Minister Bent Hoie said the app followed European regulations on data protection.

At the same time, Norway is stepping up testing from the current 30,000 weekly capacity to 100,000 by the end of the month.

Oslo last week announced a gradual lifting of strict confinement measures with schools due to reopen from April 27.

As of Thursday, Norway had 6,566 confirmed cases of COVID-19 and 130 deaths.