According to Stoltenberg, they want to do further research to determine the benefit of the vaccine for different age groups.
- We have limited information from other countries that have or have not vaccinated those over 65 so far, says Stoltenberg.
Four people have died in Norway
Norway stopped vaccination with Astra Zeneca on March 11 this year after reports of suspected side effects in some vaccinated people.
In the country, four people have died and two are being treated in hospital after receiving a combination of bleeding, blood clots and low platelet counts.
Norwegian researchers believe that this is due to a strong immune response to the AstraZeneca vaccine.
Stoltenberg says that the number of serious cases in Norway is part of what lies behind the decision to extend the break.
Denmark and Norway differ from the rest of the Nordic region
Among the Nordic countries, it is now Sweden, Finland and Iceland that have resumed vaccination.
But they will only offer it to older people.
EMA has not found a causal link
There is still no established causal link between the vaccine and the suspected side effects - blood clots in combination with a lack of platelets.
The European Medicines Agency (EMA) has investigated whether the reported health problems with Astra Zeneca's vaccine are real side effects or pure coincidences.
No causal link has been found and the vaccine is considered safe.