Mexico is bracing for the "mother of all caravans," after Interior Secretary Olga Sánchez Cordero warned on Wednesday "We have information that a new caravan is forming in Honduras, that they’re calling ‘the mother of all caravans,’ and they are thinking it could have more than 20,000 people."

The figure has been disputed by activists such as Irineo Mujica of group Pueblo Sin Fronteras, who has accompanied several caravans in Mexico and said in a statement that "there has never been a caravan of the size that Sanchez Cordero mentioned."

Olga Sánchez Cordero

According to AP, past caravans have hit "very serious logistical hurdles at 7,000 - strong."

Honduran activist Bartolo Fuentes, who accompanied a large caravan last year, dismissed the new reports as “part of the U.S. government’s plans, something made up to justify their actions.” Later Thursday, Honduras’ deputy foreign minister, Nelly Jerez, denied that a “mother of all caravans” was forming in her country. “There is no indication of such a caravan,” Jerez said. “This type of information promotes that people leave the country.” -AP

Sánchez Cordero made the comments alongside US Secretary of Homeland Security earlier this week in Miami, Florida.

Meanwhile, around 2,500 Central Americans and Cubans are currently making their way through Mexico's southern state of Chipas right now in yet another caravan. Last year's caravans contained up to 10,000 people at some points.

Mexico's tolerance for the caravans is wearing thin it seems, as they have stopped giving migrants humanitarian visas at the border, while some previously hospitable towns along the well-traveled route are have stopped allowing caravans to spend the night.

Mexican President Andres Manuel Lopez Obrador said Thursday that Mexico is doing its part to fight immigrant smuggling. “We are going to do everything we can to help. We don’t in any way want a confrontation with the U.S. government,” he said. “It is legitimate that they are displeased and they voice these concerns.” Sanchez Cordero has pledged to form a police line of “containment” around Mexico’s narrow Tehuantepec Isthmus to stop migrants from continuing north to the U.S. border. The containment belt would consist of federal police and immigration agents, but such highway blockades and checkpoints have not stopped large and determined groups of migrants in the past. -AP

System-wide meltdown

In a Thursday letter to the House and Senate, Homeland Secretary Nielsen made an "urgent request" for assistance to stop what she described as a tide of migrants overwhelming the border, according to CBS News.

"DHS facilities are overflowing, agents and officers are stretched too thin, and the magnitude of arriving and detained aliens has increased the risk of life-threatening incidents," wrote Nielsen - citing the increasing number of migrants arriving each month in large groups.

Nielsen wrote that her "greatest concern was for the children," as Customs and Border Protection currently has over 1,200 unaccompanied children in custody. The Trump administration has been widely criticized for earlier policies towards migrant children, such as separating families and keeping minors in poorly equipped detention facilities. Nielsen also asked for more detention facilities in her letter, a point of disagreement which nearly led to a second shutdown this year. Democrats have reasoned that capping Immigration and Customs Enforcement's detention beds would force the administration to narrow its ramped-up deportation efforts. Nielsen said that the Department of Health and Human Services would require more emergency resources such as medical and legal assistance to handle the influx of children. She also asked that Congress grant more authority to DHS to return unaccompanied migrant children from Central America to their countries, saying that putting these minors in the custody of sponsors in the U.S. becomes a "pull" factor for more migrants to make the trip north. -CBS News

"Let me be clear: the journey of any migrant -- especially at the hands of a smuggler or trafficker -- is not a safe one," reads the letter. "We must be able to come together on a bipartisan basis to take action."