Thousands of migrants from Central America heading for the US-Mexico border have had an offer of free bus transport to Mexico City withdrawn.
The governor of the Mexican state of Veracruz, Miguel Angel Yunes, said on Friday buses would be provided to carry migrants to the nation’s capital.
However, Mr Yunes cancelled the offer just hours later, blaming a water shortage in the city for his decision.
The caravan, now some 5,000 people, set off from Honduras several weeks ago.
They say they are fleeing persecution, poverty and violence in their home countries of Honduras, Guatemala, and El Salvador.
In a video posted to Twitter on Friday, Mr Yunes said that a “serious shortage of water” in Mexico City over the weekend meant that it would be wrong to transport the migrants there.
“The shortage will affect more than seven million people,” he said, adding that his initial offer of supplying buses would have made the situation worse.
“I would like to ask the migrants, while the problems get solved and we wait for an in-depth solution to this issue, that they accept an invitation to go to a city of Veracruz further to the south, to a bigger city where they will have adequate installations to provide them with safety.”
Responding to Mr Yunes in an open letter, the migrants said the governor’s decision to withdraw his offer to help transport people hundreds of kilometres was unacceptable.
“We consider that the argument of the shortage of water is not a valid one,” they wrote, urging Mr Yunes to “fulfil his offer”.
“The people in the caravan have walked for weeks under the rain and sun from Central America, where they left their houses and families; they were forced to leave their countries due to the violence, death and hunger,” the letter reads.
“The hard conditions, the lack of proper shelter and proper food has impacted on the health of the people,” it adds.
Earlier this week, US President Donald Trump said more than 5,200 troops will be deployed to the US-Mexico border to stop the migrant caravan.
The mid-term elections are now just days away and critics have said that Mr Trump has used the threat of illegal immigration to fire up his supporters.
At a campaign rally in Miami on Friday, former President Barack Obama accused Mr Trump of cynical politics and a political stunt over his plans to send troops to the Mexican border.
The migrant caravan set off on 12 October with a plan to trek for more than a month.
Most previous migrant caravans have numbered a few hundred people, but after a former politician posted about the plan on Facebook, news of it quickly spread and the numbers swelled.