A large caravan of Central Americans was preparing to cross the Guatemalan border into Mexico on Monday, posing a potential challenge to the Mexican government's pledge to help the United States contain mass movements of migrants.
The migrants were massed on a bridge connecting the two countries early on Monday morning in what appeared to be a tense standoff with Mexican migration officials and soldiers.
U.S. President Donald Trump has threatened to punish Mexico and Central American countries economically if they fail to curb migrant flows, resulting in a series of agreements aimed at taking pressure off the United States in absorbing the numbers.
Migrants crossed into Mexico in small groups during the weekend after Mexican security officials blocked an effort by some Central Americans to force their way through the border.
The bulk of at least 2,000 migrants remained in the Guatemalan border town of Tecun Uman, opposite the Mexican town of Ciudad Hidalgo, with some saying they planned to set off for Mexico en masse early on Monday, believing that they stood a better chance of making progress in a large caravan.
Mexico has offered migrants work in the south, but those who do not accept it or seek asylum will not be issued safe conduct passes to the United States, the interior ministry said.
The ministry said in a statement on Sunday afternoon that Mexican authorities had received nearly 1,100 migrants in the states of Chiapas and Tabasco and set out various options to them in accordance with their migration status.
"However, in the majority of cases, once the particular migration situation has been reviewed, assisted returns will be carried out to their countries of origin, assuming that their situation warrants it," the ministry said.
According to Guatemala, at least 4,000 people have entered from Honduras since Wednesday, making for one of the biggest surges since three Central American governments signed agreements with the Trump administration obliging them to assume more of the responsibility for dealing with migrants.
Mexico has so far controlled the border at Tecun Uman more successfully than in late 2018, when a large caravan of migrants sought to break through there. Many later crossed into Mexico via the Suchiate River dividing the two countries.