In the United States, the GPM is working with the U.S. Conference of Mayors, COMURES in El Salvador, and global urban networks like EFUS, Eurocities and others.

The United States Conference of Mayors (USCM) is the official non-partisan organization of cities with populations of 30,000 or more. There are 1,407 such cities in the US today. Each city is represented in the Conference by its chief elected official, the mayor. The USCM has been a strong supporter and partner of the GPM Project since its inception. The USCM provides the GPM with advice and research, while also serving as an important intermediary for United States cities.