A good question. Sanctions included other countries outside the US and EU, but I don't recall the specifics or what Norway's position was.

However, helping Iran build nuclear weapons is a very serious, very consequential thing to be doing whether or not your country is officially participating in sanctions.

Would it be ok for your company to help Mexican drug cartels, even if it was legal? This is far more serious. If Iran obtained nuclear weapons, Norway would suffer the consequences too.