"The coronavirus is out of control," the head of the army's operations centre, Rune Jakobsen, told reporters.

"We would rather preserve our army's combat capabilities so we can support society in the turbulent period to come."

The exercise had initially been expected to gather troops from a dozen NATO or partner countries, including the United States, France, Germany, Britain, Belgium and Sweden.

Organised by Norway in the far north, it was aimed at testing multinational capabilities in a high-intensity combat scenario in demanding winter conditions.

The Norwegian army wanted to "avoid being a burden on the civilian healthcare system", which had been expected to provide some personnel for the exercise, Jakobsen said.

Last week, the Norwegian army closed a military base in northern Norway after a soldier tested positive for the new coronavirus.

That is the only case detected in the Norwegian armed forces to date, but 240 soldiers are still in quarantine as a result, Jakobsen said.

On Saturday, Finland announced it would not be sending the 400 troops initially due to take part, because of the epidemic.