Generate response to the question/instruction based on a piece of given material

Question/Instruction: What is the main reason for the large amount of immigrants seeking asylum and crossing into the United States?

Given material: McALLEN — After spending more than a half-million dollars on humanitarian aid for immigrants between 2014 and 2016, the city, Catholic Charities of the Rio Grande Valley and the Food Bank of the RGV were awarded over $350,000 in federal funds, state Sen. Juan “Chuy” Hinojosa announced.
The funds are intended to reimburse for food, shelter, transportation and medical expenses that the city and organizations incurred between 2014 and 2016 due to the large amount of immigrants seeking asylum who crossed into the United States.
Of that pot of reimbursement money, McAllen will receive $141,000, according to City Manager Roel “Roy” Rodriguez.
Immigrants continue to cross into the country from Mexico, some have been seeking asylum, other adults have been criminally charged with a misdemeanor under President Donald Trump’s “zero-tolerance” policy. This new practice, which was announced this spring, has separated about 2,300 children from their parents.
Rodriguez said the city is no longer spending any money on humanitarian aid. In previous years, the center that temporarily housed immigrants operated out of Sacred Heart Catholic Church. It has since moved several blocks away near the corner of Bicentennial Boulevard and Beaumont Avenue, and is operated by Catholic Charities of the RGV.
“After years of effort, I’m pleased that the city of McAllen, Catholic Charities of the Rio Grande Valley and the Food Bank of the Rio Grande Valley have finally been reimbursed by the federal government for some of the costs they incurred in responding to the influx of unaccompanied children and families from Central America between 2014 and 2016,” Hinojosa said in a statement.
In October 2017, McAllen commissioners voted to resubmit an application to Gov. Greg Abbott’s office for a $719,000 immigration humanitarian aid reimbursement. McAllen made several attempts to get reimbursed by the Federal Emergency Management Agency.
U.S. Rep. Henry Cuellar, D-Laredo, grew frustrated with Abbott’s inability to funnel FEMA’s reimbursement to McAllen for years. So Cuellar wrote Abbott a letter in July, 2017.
“I understand that there was a misunderstanding between the Federal Emergency Management Agency and the governor’s office that led to the assumption that the use of FEMA’s State Homeland Security Program federal funds to reimburse communities was not allowed,” the letter stated. “I have since contacted FEMA to provide further clarification to the State of Texas stating that border communities are allowed to be reimbursed for their humanitarian assistance going back to 2014.
This prompt doesn't seem malicious.