Migrants who crossed into the U.S. from Mexico wait to be processed by U.S. Border Patrol agents, Thursday, Sept. 21, 2023, in Eagle Pass, Texas. (AP Photo/Eric Gay)
CNN  — 

Migrant crossings at the US-Mexico border are expected to remain high in the near term, according to a senior US Customs and Border Protection official, who noted that additional commitments from Mexico are expected to help eventually drive down numbers.

Federal authorities continued to grapple with a new surge of migrants over the weekend, following a wave of newcomers last week. On Sunday, Border Patrol agents arrested close to 9,000 people and apprehended around 7,500 people on Saturday, a Homeland Security official told CNN. The Del Rio and El Paso sectors are among the busiest along the US southern border.

“In the near term, we’d expect that numbers will probably stay somewhere close to where they were last week, as some of these things take effect,” the senior CBP official said, referring to increased enforcement by Mexico.

“As they take effect, it will start to influence people’s calculus about whether or not they should leave where they are right now, sell their belongings, leave their homes, and move towards the US southwest border,” the official added.

The official noted that the agency is operating in a “resource constrained environment,” and as a result, release of migrants as they go through their immigration proceedings has ticked up.

“We’ve not received additional resourcing despite having sought it in the supplemental from the Hill in order to be able to expand the capacity within CBP and ICE and USCIS to increase our capacity for things like expedited removal,” the official told CNN.

Officials had been monitoring the number of migrants crossing the treacherous Darién Gap – which connects Panama and Colombia and has recently served as a barometer for movement in the region – and expected an increase of crossings at the US southern border. But the surge of migrants, who are mostly from Venezuela, continues to place a strain of federal resources.

The official said migrants have increasingly used trains in Mexico to journey to the US southern border as a result of human smuggling organizations who’ve advertised that mode of transportation on social media.

Over the weekend, the US secured commitments from Mexico to double down on enforcement and assist in depressurizing the border, through a series of actions including mirror patrols, repatriation flights and conducting interventions on railways and highways.

“We are working closely with our partners to the south to do everything we can and to seek that they do everything they can to disrupt and interdict that movement, because it is being fueled by a series of cartels that are making significant amounts of money profiting off of vulnerable individuals, and really wreaking havoc in a number of places, including creating some really challenging situations throughout Mexico,” the senior CBP official said.