Up to 15,000 may join largest ever migrant caravan to walk through Mexico to US

Thousands of people huddled together for protection move north as leaders gather for Biden's Summit of the Americas in LA

Liozanys Comeja credits her survival to her teacup chihuahua, Mia. Originally from Venezuela, Comeja moved to Colombia five years ago, but decided to leave her new life behind this month due to the rising cost of living. She crossed the Darien Gap, a notorious stretch of jungle between Colombia and Panama, with Mia tucked in her backpack, eventually making her way across eight countries. Now, Comeja is hoping the dog will help her make it through the grueling final leg of their journey.

Comeja has joined about 11,000 others who on Monday will leave Tapachula, a sweltering city on the Mexico-Guatemala border, and head north for the United States. It will depart as leaders from across the hemisphere gather in Los Angeles for the Summit of the Americas.