This weekend, Mayor Zohran Kwame Mamdani joined mayors from across the United States and around the world to close the 2026 Urban 20 (U20) Mayors Summit, where city leaders ratified a communique outlining what cities are already doing to confront the housing affordability crisis, climate change and migration - and what national governments must do to give cities the tools to do more.
New York City and Los Angeles co-chaired this year's U20, convened by C40 Cities and United Cities and Local Governments (UCLG). Over three days, 25 mayors, deputy mayors and senior city leaders representing 34 cities across G20 countries met in New York to share what is working in their cities and establish a common agenda for national governments. Representatives from national governments, the United Nations and other international organizations were invited to respond to the communique following its ratification.
The communique centers on three priorities: expanding access to secure, dignified and affordable housing; confronting the climate crisis through a clean and just energy transition and stronger urban resilience; and protecting immigrant and displaced communities while managing migration with dignity and humanity.
"People experience government through the rent they pay, the energy bill on their kitchen table, whether their children are safe when they leave the house and whether their family can build a good life," said Mayor Mamdani. "That is why it matters that mayors from around the world came together in New York to say that cities need the power and resources to deliver for the people we serve. We know what is possible when government works for working people. Give cities the tools to meet these challenges and we will rise to the occasion."
Across each priority, the message from mayors was clear: Cities are already doing the work. National governments must give them the authority and resources to do more.
- On housing: U20 cities called on national governments to give local governments greater authority over their housing markets, including through tenant protections, rent stabilization and rent control, limits on short-term rentals and inclusionary zoning. Mayors also called for predictable public funding and direct access to housing finance through multilateral development banks, allowing cities and nonprofit housing institutions to access resources without having to go through national governments first.
- On climate: Mayors highlighted the central role cities play in cutting emissions and protecting residents from extreme heat, flooding and other climate hazards. They called for cities to be eligible recipients of multilateral climate funds, to have a formal role in national climate and energy planning, and to have access to the meteorological and public health data needed to operate early warning systems and protect residents.
- On migration: The communique rejects the political narratives that stigmatize newcomers and recognizes the contributions migrants make to cities and economies around the world. Mayors called for dedicated funding for reception and integration, a meaningful role for cities in shaping migration policy, and coordinated access to housing, health care, education and work for migrants and displaced people, in partnership with the community already doing this work.
The communique represents cities serving more than 500 million people - over a third of global GDP - and calls on mayors to stand with locally elected leaders facing threats, intimidation, political persecution or removal from office for exercising their democratic mandate.
"The 2026 Urban 20 has shown what cities can accomplish when we come together around the challenges our communities face every day. From housing affordability and climate action to supporting immigrant communities and creating good jobs, mayors are on the front lines, developing practical solutions and delivering results. In Los Angeles, we are putting that work into action - from going coal-free and doubling EV chargers citywide to creating capacity for half a million new homes through our historic rezoning program," said Los Angeles Mayor Karen Bass. "The U20 Communiqué turns that shared experience into a collective call for action, giving cities the tools, resources, and partnerships they need to go further and faster. Los Angeles is proud to have co-chaired this year's U20 with New York City, and we will carry this work forward with cities around the world."
"Mayors came to New York from different countries and different circumstances, but the pressures facing our residents are remarkably similar: rising costs, extreme heat, housing insecurity and displacement," said Mayor Yvonne Aki-Sawyerr of Freetown, Co-Chair of C40 Cities. "This communiqué turns that shared experience into a shared agenda for action. Cities are ready to deliver. Give us the tools and resources to act, and we will."
"The spirit we need to carry forward is one of cooperation over division, solidarity over isolation, and shared responsibility for protecting our communities," said Mayor Ugur Ibrahim Altay of Konya, President of United Cities and Local Governments (UCLG). "A stronger multilateral system is needed. It will need to trust cities, work with them and design solutions that can be delivered through them. That is the present we are shaping every day and the future we are committed to delivering"
"Public service delivery is about shaping communities in which people can live with dignity. That is precisely why the three priorities of this U20 cycle matter: they speak directly to the conditions that shape people's daily lives and to the capacity of our cities to protect dignity, opportunity and belonging," said Emilia Saiz, Secretary General of UCLG.
The close of the U20 Summit opens a week of city climate leadership in New York as mayors join leaders from government, business and civil society for Climate Week NYC, which runs from September 20-27. Throughout the week, C40 mayors will continue work on extreme heat and weather resilience, clean air and sustainable housing and set the stage for COP31, where cities will continue pressing national governments to match their ambition.
