The city has developed a concept of international co-operation and maintains sustainability oriented project partnerships instead of traditional city twinning, among others with Chengdu (China), Minsk (Republic of Belarus), and Ulan Baatar (Mongolia). These joint projects have a sustainable development orientation - such as the energy efficiency project involving schools in Bonn and Bukhara (Uzbekistan), the lifeweb project for biodiversity and climate change adaption in La Paz (Bolivia), and the renaturation of the Fosu lagoon in Cape Coast (Ghana).
What fills these project partnerships with life is civil-society commitment on both sides. Friendly ties and reliable networks have evolved that are lasting, supportive and very enriching for these partnerships. The cultural exchange that has been established between Bonn and its project partner cities also contributes considerably to their success.
All project partnerships are coordinated by the Department of International Affairs and Global Sustainability of the City of Bonn. Cooperation among senior city representatives, administrative staff and civil society ensures that sound ideas and sustainability plans can be brought to and implemented in the everyday lives of the people.
So Bonn´s central theme is sustainability - and the city practices what it preaches. It joined the city network ICLEI and the Climate Alliance of Cities. Bonn is involved in the international network LAB Local Action for Biodiversity and in the Global Partnership on Local and Sub-national Action for Biodiversity. In addition, the Mayor of Bonn was elected Vice-Chairperson of the World Council of Mayors on Climate Change in 2009.
On February 9, 2023, the Council of the City of Bonn decided by unanimous vote to enter into a solidarity partnership with the Ukrainian city of Kherson
In addition, Bonn has maintained friendly ties with Tel Aviv-Jafo (Israel) since 1983.
Moreover, the city cooperates with other cities on a case-by-case basis within the framework of special projects. Currently cooperation is taking place in particular with Ramallah (Palestine).