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.