RIO DE JANEIRO - Latin America and the Caribbean need to prepare for a new urban transition after decades of the accelerated growth of cities and unsatisfied social demands, the UN Human Settlement Program (UN-Habitat) said on Tuesday.

The UN-Habitat said in a report titled "State of Latin American and Caribbean Cities", presented Tuesday in Rio de Janeiro, "Urban transition in the region has been characterized by its speed. While it has brought greater job opportunities and improved living conditions to large sectors of the population, it has incurred a high social, economic and environmental cost."

"To move towards a model of cities that are more sustainable, more compact, that provide urban centers with greater mobility and energy efficiency, we need to reaffirm the collective interest in urban planning, work on social and territorial cohesion policies, and develop national urban policies," said the report.

According to the report, the region is the world's most urbanized, with 80 percent of its population (468 million people) living in cities plagued by inequality.

"The biggest problem detected by the study is that cities are not fighting the inequities. Several Latin American cities have the highest rates of inequality in the world," said Erik Vittrup, head of the UN-Habitat.

She also stressed that without a profound change in the trend, lack of housing will continue to be one of the region's biggest challenges over the next few years.

Vittrup said the new model for Latin American cities should seek greater density, by building more high-rises and not invading more land in the suburbs to build single-story homes, which would help minimize environmental problems and real estate speculation.

The report also predicts that by 2050, 89 percent of the region's population will live in cities, while the 111 million people who currently live in poor neighborhoods will see their numbers increase.