UN Secretary-General Antonio Guterres delivered a video message at the opening of the 13th Session of the World Urban Forum (WUF13).
He noted that about three billion people live in inadequate housing.
Developing economies are not immune to homelessness.
Recalling his student days volunteering in poor neighborhoods of Lisbon, Guterres said: "We must fight inequalities by providing adequate, safe, and affordable housing. Housing is a human right. WUF13 can be a boost to turn this goal into reality."
