TORONTO, Oct 28 (Thomson Reuters Foundation) - Managing migration to the world's growing cities is the biggest challenge of the 21st century, with three million people moving to urban areas every week, competing for services, jobs and sanitation, the International Organization for Migration (IOM) said on Wednesday.
The planet's urban population is expected to rise to 6.4 billion by 2050 from 3.9 billion today, IOM said in its annual report.
The number of people living in slums has risen to 863 million today from 650 million in 1990, it said, underlining the potential pitfalls of urbanization.
Providing proper services to these migrants will be a key challenge for governments, the IOM said.
About half of the world's 232 million international migrants live in 10 highly urbanized, high-income countries including Australia, Britain, Canada, the United States, France, Germany, Russia and Saudi Arabia, the report said.
However, most migration occurs within countries rather than across borders with the United Nations estimating that 740 million people are internal migrants.
The IOM said patterns of migration are changing as more people move within and between developing and middle-income countries, drawn to their growing economies.
"Migrants are increasingly attracted to cities in countries experiencing higher economic growth in East Asia, Brazil, southern Africa and western India," June Lee, the report's editor-in-chief, said in a statement.
"We need to consider what roles international communities and organizations play (in making urban growth inclusive and positive)," she said.
Almost all of the growth in the world's population, an expected 2.5 billion over the next few decades, is expected to come from urban areas in low and middle income countries, particularly in Africa and Asia, the report said.
(Reporting By Chris Arsenault; Editing by Katie Nguyen; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's rights, trafficking, corruption and climate change. Visit www.trust.org)
Our Standards: The Thomson Reuters Trust Principles.