The UN is just a glorified board room for countries to discuss things, it has no executive powers over its permanent security council members and their allies.
Basically, the UN can declare whatever they want, but there's nothing stopping the likes of US and Russia to ignore it and do the opposite of that.
It's the League of Nations all over again. Nothing has been learned.
It also spent the last few years making the problems out there worse. They are themselves complicit in this outcome.
There are no winners in this conflict on either side.
I know there is Paltel in West Bank; but I don't know if they are still operating in Gaza.