Authorities south of the US border have stepped in to offer aid in the form of food, shelter, medical care, as well as education and jobs to those in need.
But the thousands of Central American migrants have reportedly refused all offers of help – saying they want to get to the United States.
Mexico’s President Enrique Pena Nieto made the generous offer on Friday, telling the caravan migrants they could apply for refugee status in his country provided they agreed to stay in the two southern states.
However, a show of hands vote held in the town of Arriaga saw hordes turn down any help, with the majority insisting their final destination had to be the US.
According to news reports, the migrants yelled “no thank you” when presented with the offer, adding they are “heading north”.
Mexican authorities said approximately 8,000 people are walking towards the border, with a further 1,000 following behind.
The country has allowed them to travel across its territory but has so far refused to offer any aid, insisting that must be for those who register legally.
US Defence Secretary Jim Mattis has now authorised the use of troops and other military resources at the southern border as the Government seeks to stem the flow of people illegally crossing in the US.
The US military said Secretary Mattis had authorised the military to provide “mission-enhancing capabilities” to US Customs and Border Protection, including engineering support to help build temporary barriers and housing.
It is unclear if the soldiers will be armed.
President Donald Trump has taken a strong line on the migrant issue, writing on Twitter that he was “bringing out the military for this National Emergency. They will be stopped!”
The caravan, which began in Honduras nearly two weeks ago and picked up other Central Americans along the way, has angered Trump, who has maintained a hard-line on immigration.
Congressman Adam Smith, the top Democrat on the House Armed Services Committee, condemned the mobilisation of forces.
“There is absolutely no reason to further politicise and militarise this humanitarian crisis,” he said.