Trump promises to stop the caravan of migrants. But his administration is struggling to do it.

President Trump's attempts to politically blame Democrats for a caravan of thousands of Central American migrants to the United States have masked growing concern in the White House about how to manage a potentially unprecedented mass on the southern border .

Trump and his associates convened high-level emergency meetings to put in place an effective response to put an end to the group of men, women and poorly organized children who are traveling slowly in Mexico. The main goal was to pressure the Mexican authorities to disperse the migrants, but the president also implored his aides to develop a more forceful plan to prevent the group from entering the United States. said several senior officials of the administration informed of the deliberations.

"They will not succeed in illegally entering the United States, whatever that may be," US Secretary of State Mike Pompeo told reporters this week, saying that he "s not going to get into the United States anyway," he said. had met twice with his Mexican counterpart, Luis Videgaray, since their meeting in Mexico City last week. .

The caravan, which remains very fluid and disorganized, would reach the United States. A day after the United Nations estimated the group at 7,200 people, Mexican officials announced on Wednesday that it had about 3,630 people, and 3,500 applications were processed.

The caravan, which comes from Honduras, travels mainly on foot, which means that their arrival at the US-Mexico border could still be done in a few weeks. Without any official leader, the group could also disperse and disperse along the way, experts said, with some migrants choosing different routes: staying in Mexico, taking alternative routes, or leaving and returning home. This would make the situation more manageable for US authorities.

"The goal is to get maximum pressure on Mexico," said a Trump administration official, who requested anonymity to describe sensitive discussions.

"I think we will know in the next 48 hours whether they will do something or not," the official said, noting that migrants will have more and more trouble turning around in Mexico.

But Roberta Jacobson, US ambassador to Mexico from June 2016 to May last, said that there was only one month left to President Enrique Peña Nieto. The new administration of the leftist Andrés Manuel López Obrador said he wants to focus on promoting development in Central America and not on border control tactics.

"Obviously, there is not much incentive to do anything really radical that will become very unpopular, as would be more energetic measures," Jacobson said.

Senior Trump administration officials have expressed concern over images this week of migrants crossing a security gate in northern Guatemala and crossing a bridge, some jumping inside and wading in a river to enter Mexico.

Trump said the scene was related to "grief on both sides" and added that she "spells in Congress: something must be done. You can not do that. "

Although the size of the caravan remains relatively small compared to the total number of unauthorized immigrants arrested each month at the southern border of the United States – more than 50,000 were arrested in September, according to the Department of Homeland Security – The arrival of thousands of people in a single group, accompanied by a phalanx of international journalists, could create a humanitarian challenge and a political crisis for the White House.

It could also become a powerful lever if Trump succeeds in imposing a partial closure of the government following a battle to secure funding from the wall of his wall by the Congress during the Parody Congress session after the mid-term elections.

Democrats have warned that Trump is fueling public fears by exaggerating the threats posed by migrants; The president admitted that he found no evidence to support his public claims that criminals and potential terrorists were part of the caravan.

Amy Pope, who, as assistant counselor for homeland security in the Obama administration, helped coordinate an emergency response to a resurgence of unaccompanied minors in 2014, said the Central American caravan would not was not a threat to national security.

"These are not people who are attacking the border," she said. "They present themselves [to Border Patrol agents] and apply for asylum. I think the best solutions are those in which we work with Mexico to find a way to manage the identification of people who should get asylum. "

Trump's response so far, she added, was "more of a mess and politics affair" to rally her conservative base before the mid-term.

In this week's Twitter messages, Trump suggested sending troops to the border and cutting back on aid to Guatemala and Honduras, or even Mexico, for failing to stop the caravan. Some 2,100 National Guard soldiers were deployed to the border mission after the president cleared the move in the spring, although it is difficult to determine whether Trump plans to add other guards. or to use other military means.

Officials from the State Department and the Pentagon said this week that they had not received any new White House guidelines.

Behind the scenes, senior government officials have recognized that such measures would have minimal effect on stopping global flows in Central America.

During the fiscal year ended last month, US authorities arrested a record 107,212 family members from Central America on the southern border, erasing the previous record of 77,000 registered in 2016. Experts said the soaring prices were caused by deteriorating conditions in Honduras, El Salvador and Guatemala. including gang violence, organized crime, poverty and hunger.

[Migrant caravan: Why thousands of Central Americans are walking to the border]

But Donald Trump's aides blamed US laws for being too lenient in allowing Central American families to stay in the United States and said the only way to mitigate the impact of the borders would be for Congress to change the rules. laws to accelerate deportations.

By law, the legal guarantees available to unaccompanied families and minors in non-US countries are superior to those offered by Mexico or Canada. In most cases, after seeking asylum, they are released inside the country waiting to be heard by an immigration judge – a process that may take more time. One year because of the considerable backlog.

"The administration wants to be able to repatriate entire families from Central America, as well as minors, after their arrest," said a senior administration official during a briefing with the journalists. In doing so, he added, it would send a powerful message of deterrence that would deter others from embarking on expensive and dangerous journeys.

"If we could do that, there would be no border crisis," said the official.

But humanitarian groups have challenged this strategy. In 2000, about 95% of the immigrants apprehended at the border came from Mexico, most of them being single men looking for a job, according to DHS officials. Last month, nearly 50 percent of arrested immigrants came from Central America, most families with children, officials said.

Wendy Young, executive director of Kids in Need of Defense, said federal laws have been enacted to provide better guarantees for these vulnerable populations.

"The immigration system can not be unique," she said.

Josh Dawsey, Dan Lamothe and Carol Morello contributed to this report.