The U.S. Customs and Border Protection said Sunday that the agency's top official has met with authorities in Mexico to work on ways to better secure their shared border.

Acting CBP Commissioner Troy Miller traveled to Ciudad Juarez, a Mexican city on the Rio Grande, just south of El Paso, Texas, where he met with senior officials from the Mexican government and the railway industry on Friday.

During those discussions, Miller "urged coordination of efforts to diminish surging irregular migration, and continuation of lawful trade and travel while reiterating the need for coordinated engagement -- to include mirrored patrols with local Mexican law enforcement agencies," CBP said in a press release.

Miller also "noted his appreciation for the continuing attention to dangerous migrant travel aboard railcars" and "discussed the impact that increased resource needs being devoted to processing inadmissible noncitizens has on CBP's enforcement mission and operations at the ports of entry," according to the press release.

"We are continuing to work closely with our partners in Mexico to increase security and address irregular migration along our shared border," Miller said in a statement Sunday. "The United States and Mexico remain committed to stemming the flow of irregular migration driven by unscrupulous smugglers, while maintaining access to lawful pathways."

On Saturday, CBP announced the resumption of operations at the international railway crossing bridge in Eagle Pass, Texas.

The United States has been grappling with a surge of unauthorized crossings of migrants at its southwestern border after so-called Title 42 restrictions expired in May, when the federal government lifted the national public health emergency for COVID-19.

The restrictions were a pandemic-related immigration policy that allowed the U.S. to swiftly turn back migrants at its border with Mexico for the last three years in the name of protecting public health.

Many of the migrants are fleeing poverty and hardship in their home countries in Central and South America, but some are coming from as far as Asia.

ABC News' Luke Barr contributed to this report.