I am not a native speaker but have come across it. https://wordhistories.net/2017/07/20/neither-fish-nor-fowl-origin/
"Het is vlees noch vis" and similarly: "Het is hom noch kuit", are expressions often used when a (policy-) decision does not reflect a clearcut choise for one-or-the-other solution to the problem and in fact requires a follow-up. I have the feeling this is not the same for the Norwegian phrase though.
Neither ... nor is a tricky one. It fell out of favour in English teaching circles (UK / Scotland) when I was being taught in the 70s & 80s. It's essentially a contraction of "neither ..., nor is it ...". I don't know if it's back in vogue or this is a US English difference but I have a visceral reaction against it. Much like pluralising 'roof' as 'roofs' (when it should be rooves, like hooves).