The 12th session of the World Urban Forum or WUF12, the United Nations' premier global conference on sustainable urban development ,opened on Monday in Egypt's capital Cairo, a megacity renowned for its long history of urban growth and transformation.

Themed, "It all starts at home: Local actions for sustainable cities and communities", the forum brought together more than 37,000 participants from over 182 countries, including national and local government officials, urban planners, business leaders, academics and civil society organizations.

The weeklong meeting will spotlight the importance of local solutions in addressing global urban challenges.

With five years left to achieve the Sustainable Development Goals, the forum will focus on localizing the SDGs, promoting partnerships and coalitions and catalyzing actions that translate global ambitions into local impact.

Speaking at the opening press conference, Anaclaudia Rossbach, the executive director of UN-Habitat, said the global housing crisis, affecting almost three billion people, is of paramount concern.

She said transforming informal settlements and slums as well as addressing homelessness is a must.

"To do so, we must work together. The World Urban Forum is the perfect platform to scale and build coalitions and partnerships for impact," she said.

"It is the biggest coalition in support of transformative change, needed to overcome the global housing crisis and give an urban contribution to the major crises we face, such as climate, conflicts and poverty."

Antonio Guterres, the UN secretary general, said cities generate 70 percent of greenhouse gas emissions and that municipal waste is set to rise by two-thirds within a generation.

"Not only are cities powerful engines of social and economic development, they are also catalysts of sustainable solutions. I invite you to seek innovations and inspiration and take them back to your communities," he said in a pre-recorded video address.

Manal Awad, the Egyptian minister of local development, said WUF12 serves as a valuable platform to highlight the rich cultural and architectural heritage of Cairo, as well as the significant advancements and developments that have taken place in the city over the last decade.

He said collaboration among community groups and partnerships with the private sector are essential for developing innovative and effective solutions to urban challenges, thereby fostering inclusive growth and resilience in urban areas.