UN small arms treaty
This will be coming before the senate for ratification. I can tell you there will be strong pressure to get the senate to do so, and there will be a lot of deception to make it seem like it will not affect gun owners (it will, especially in imports of guns and ammunition from European countries.)
I hear about it in the news and there is an brief on what it contains but I am sure there is plenty of room to amend it to increase restrictions later on, if it isn't already overbearing as it is.
The UN makes up rules as it goes along.