Migrants from around the world converge on remote Arizona desert, fueling humanitarian crisis at...

A remote desert region along the southern border has become a makeshift international arrivals area for thousands of migrants from Africa, Asia and Latin America hoping to work and reunite with family members in the U.S.

Over the past few days, large groups of migrant men, women and some families with children have spent the night in a makeshift staging ground in this rugged section of the U.S.-Mexico border, waiting for overtaxed border officials to process them. Many expect to be released into the U.S. after being vetted by local Border Patrol agents, who lack the resources and manpower to screen everyone in a timely manner.

Most of the migrant men hailed from African countries, including Guinea, Mauritania, Morocco and Senegal, as well as some nations in Asia like Bangladesh, India, Nepal, Pakistan and Syria. Some men had left their hometowns in Ecuador and other parts of Latin America. The families traveling with children were predominantly Mexican and Central American.

The migrants set up fires at night and in the early morning hours to keep warm amid dropping temperatures. Many of them brought blankets to sleep next to the border wall. Without restrooms, they relieved themselves near the cacti that adorn the picturesque landscape of this national monument, located two hours away from the closest U.S. city.