"Better hurry up, you have <18 months to agree a deal ..."
Not sure, but I think that's dealt with by the UN Economic Commission for Europe
https://www.unece.org/info/ece-homepage.html
Incidentally, unlike the EU, this body does not have a parliament directly elected by citizens of the member states. And it probably employs lots of unelected bureaucrats too :) Now, what was that about Taking back Control? Another referendum to leave the UN? (https://www.unece.org/mission.html : UNECE's major aim is to promote pan-European economic integration.)