The first migrants from a large group of people travelling through Mexico towards the United States have arrived in the capital, Mexico City.
About 450 people, mostly men and boys, have been given temporary shelter at a sports stadium.
The group, known as a caravan, set off from Honduras several weeks ago and is now about 5,000 strong.
US President Donald Trump says troops will be deployed to stop them crossing the US-Mexican border.
Critics have accused Mr Trump of using the threat of illegal immigration to fire up his supporters ahead of Tuesday’s mid-term elections.
The migrants says they are fleeing persecution, poverty and violence in their home countries of Honduras, Guatemala, and El Salvador.
Many of those arriving in the Jesús Martínez Palillo stadium on Sunday had walked or hitched rides from the state of Veracruz.
“From what I brought from Honduras I have nothing. Even yesterday I walked barefoot,” Kenia Alvarado, 21, told El Universal newspaper after arriving at the stadium.
Veracruz Governor Miguel Ángel Yunes said on Friday that buses would be provided to take migrants to the capital – but the offer was later withdrawn.