In 2018, Norway’s Parliament “requested the Government to review the consequences for Norway of ratifying the recently adopted Treaty on the Prohibition of Nuclear Weapons.” Here’s the report.
Here’s the assessment:
The Government attaches great importance to Norway’s Nato obligations. Nato membership is the cornerstone of Norway’s security and defence policy, and the Alliance must not be undermined. Ratification of the Treaty on the Prohibition of Nuclear Weapons by Norway or by any of the other Nato Allies would cause divisions in the Alliance. This would primarily serve the interests of countries that pose a security threat to Norway and other Nato members.
Norway and Nato share the goal of achieving and maintaining a world without nuclear weapons. This process will depend on the participation of all countries that have nuclear weapons. If Nato were to abandon its own nuclear deterrence but nuclear-weapon states outside the Alliance did not, this would make Norway and the Alliance vulnerable and create a dangerous strategic imbalance. Given the strategic importance of nuclear weapons in security policy, the Treaty has limited potential as a tool for applying political pressure.