Organizing international mayor’s conferences in the framework of major international conferences has become a tradition in Bonn to share experience and expertise and to make the voice of cities heard.

Like in 2008, when four mayors from four continents brought the Bonn Call for Action into the 9th Conference of the Parties on Biological Diversity in Bonn.
Like in 2017, when cities, towns and regions adopted the Bonn-Fiji Commitment during the 23rd United Nations Climate Change Conference in Bonn to jointly advance climate action around the globe.