The United States imposed harsh new immigration laws on Friday, leaving desperate migrants at its southern border with an unclear future, even as a top official voiced confidence in the system's stability.

Thousands of migrants remained in Mexico, seeking to reach the United States, as it remained unclear how strict new regulations for illegal border crossers would be implemented.

In Ciudad Juarez, Mexico, the US military barred 200 migrants from entering Gate 42, the entrance point to El Paso, Texas, where hundreds passed on Thursday.

The death of an unaccompanied migrant kid in the custody of Health and Human Services, which cares for minors who enter the nation alone, was reported by US officials.

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The agency provided no more information, however, Honduras Minister of Foreign Affairs Enrique Reina stated that a 17-year-old Honduran teenager died in an HHS facility in Florida.

When the US lifted Title 42 on Thursday, Homeland Security Secretary Alejandro Mayorkas declared that the "border is not open."

The Biden administration and the Texas state government are sending troops to the US-Mexico border in anticipation of a spike in illegal immigration after Title 42 ended on Thursday. 

Hundreds of specialist investigative agents and air marshals from the United States Department of Homeland Security (DHS) are being taken away from their day-to-day jobs to assist with border management, according to reports, prompting some employees to object, claiming they are being transferred to menial chores.

Last week, the Biden administration relayed that although the Trump-era restriction will be lifted, that does not insinuate that the border will be open.

The rule change reinstates a decades-old regulation known as Title 8, which permits border crossers to request asylum, as well as tough new criteria that many believe would speed up deportations and punishments.

Washington believes that the new measures, paired with additional legal avenues, would help to curb the massive influx of migrants to the US-Mexico border, where hundreds of thousands have attempted to cross every month in the last year.

Mayorkas stated that people who chose unlawful pathways to enter will face tougher consequences including a 5-year ban on re-entry and criminal prosecution.

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Gabriel Landaeta, 22,was among those near Brownsville,

"If someday someone makes a documentary, let them put that the Venezuelan with a good heart came here looking for happiness," he told AFP.

Washington is establishing regional processing centers, expanding guest worker programs, and increasing refugee admissions from Haiti, Cuba, Venezuela, and other difficult nations to offer additional legal avenues.

CBPOne, an app for arranging immigration interviews at the border, has been released for asylum applicants.

While many have complained about technical difficulties, Venezuelan Carlos Palacios, 38, arrived in Brownsville on Friday for his CBPOne appointment.

"Everything is fast and efficient," he stated. "We opted to make the appointment, waiting to do things legally."

"Crossing the river does not ensure you get in, as I am doing now."

Mexican Foreign Minister Marcelo Ebrard says the number of migrants crossing is decreasing, adding that "the flux is dropping today. We have not had confrontations or situations of violence on the border."

Olga Sarrado, the spokeswoman for the UN refugee agency, told a briefing in Geneva that "the Americas... are going through an unprecedented displacement crisis," adding that "just decisions from one single country are not going to fix the challenges and we cannot forget that these are human beings."