The US-Mexico border is the world’s deadliest land migration crossing, according to figures released today by the UN migration agency, with hundreds of people dying trying to make the perilous desert crossing.

In a region of vast deserts, canyons, rivers and cactus-studded hills, migrants often suffer from heatstroke in the summer months and hypothermia in the winter, according to U.S. Border Patrol officials. Some bodies are never found.

The International Organization for Migration (IOM/IOM) recorded 686 deaths and disappearances between migrants at the border last year. Most of the victims on the Caribbean migration routes are people from the Dominican Republic, Haiti and Cuba.

The number of deaths and disappearances recorded by IOM along the border represents nearly half of the 1,457 incidents recorded across the Americas last year.

However, the actual number is likely higher as data is missingincluding data from the offices of the Texas Border Coroner and the Mexican Search and Rescue Agency.

Paul Dillon, a spokesman for the IOM, said the figures recorded “represent the lowest estimates available”.

“The alarming figures are a stark reminder of the need for decisive action to establish regular legal migration routes,” he told reporters in Geneva.

The IOM reported that about half of the deaths recorded last year were linked to crossing the Sonoran and Chihuahua deserts.

According to the IOM, 141 migrant deaths were recorded in the Darien jungle between Panama and Colombia last year.

“The remote and dangerous nature of the area and the presence of criminal gangs along the route means that this figure may not represent the true number of lives lost,” Dillon said.