The Desperate Trek

Makeshift rafts, made of wooden planks and inner tubes, carry passengers across the Rio Suchiate.

Migrants jump off a raft onto Mexican soil at an illicit crossing point along the Mexico-Guatemala border.

An average of more than 1,500 migrants a month — from Asia, Africa and Haiti—have been arriving in Mexico’s southern Chiapas state, across the Rio Suchiate from Guatemala. Mexican officials say they have never before seen such a surge of non-Latin Americans here.

Migrants from Africa and Haiti board a van to take them 30 miles north from the Mexico-Guatemala border to Tapachula.

Migrants on their way to Tapachula, a bustling, sweltering Mexican city in the shadow of the Tacaná volcano.

Migrants register to get an official exit letter at Mexico’s National Institute of Migration in Tapachula.

Women wearing the distinctive headdresses of their African homeland arrive in Tapachula.

Concepcion Gonzalez Ramirez, also known as “Mama Africa,� is the manager of The Imperial, one of many budget hotels serving the migrant trade in Tapachula.

Migrants from Africa, Haiti and Asia wait in line to get an exit letter from Mexico.

Mexico has adopted what officials call a “humanitarian� policy granting most of the new arrivals a 20-day window to leave the country — enough time, in theory, to make it to the United States.

Ibrahim Anyars, right, a tailor from Ghana with three children, at the Bangladeshi Restaurant in Tapachula. Along the way, Anyars’ older brother, Rafik Ibrahim, drowned while trying to cross a river in the South American jungle.

Migrants board charter buses that will take them to the U.S.-Mexico border.

Munawar Abbas at the Bangladeshi Restaurant in Tapachula. Abbas left his Pakistani homeland in May in hopes of reaching the United States.

The Palafox Hotel, with rooms starting at $12 a night, is one of many budget hotels serving the migrant trade.

Aisha Abdul-Lahi, from Somalia, in her hotel room at the Palafox Hotel. Abdul-Lahi says she fled an abusive marriage to a man 30 years her senior, leaving behind two small children.

A convenience store frequented by many of the migrants in Tapachula.

Kamran Akram, far right, left the Punjab region of Pakistan in December 2014, spending 15 months in Brazil before leaving for Mexico.

Most of the “extra-continentals� turn themselves in voluntarily to Mexican authorities, forming orderly queues each morning outside the federal immigration detention center in Tapachula.

Migrants from Africa and Haiti wait for a bus to take them to the U.S.-Mexico border.

Migrants from Africa and Haiti walk toward a charter bus that will take them to the U.S.-Mexico border.

Migrants board public transportation that will take them 30 miles north of the Rio Suchiate to Tapachula.

Mexico has seen a striking increase in what officials refer to as extra-continentales, or non-Latin Americans, all destined for the U.S.

After resting in Tapachula, near the Mexico-Guatemala border, migrants continue their journey north to the U.S.

Manoucheca Desir, of the Democratic Republic of the Congo, is one of the many Africans who are seeking a better life in the U.S.