An aerial view of Cancun, Mexico, in July 2020.
CNN  — 

US border authorities have been deployed to assist Mexican immigration officials in spotting travelers arriving in Cancun, Mexico, with the intention of continuing to the US southern border, according to two Department of Homeland Security officials.

The effort is part of a multi-pronged approach to stem the flow of migration to the US-Mexico border following consecutive months of increasing arrests. In May, border authorities encountered around 180,000 migrants on the southwest border, according to one of the officials, putting the US on track to surpass 2019 crisis numbers with four months left in the fiscal year.

The expansion to Cancun is part of an existing program to position US Customs and Border Protection officers with their foreign counterparts in “strategically placed locations” where they work alongside immigration authorities to identify people who are likely heading toward the US with the intent to enter illegally, according to one of the Homeland Security officials.

Cancun has been on the “radar screen” for some time, according to a former Customs and Border Protection official, because it has one of Mexico’s major airports with significant international travel. Expanding to Cancun was “long in the works” because US officials had identified it as one of the routes used by people who illegally cross the US southern border, the DHS official added.

It underscores the evolving landscape of migration and the various methods used by migrants to arrive at the US southern border. Vice President Kamala Harris is diving into those challenges this week during her first foreign trip, sending a blunt message to migrants while in Guatemala: Don’t come.

The trip to Guatemala and Mexico underscores the Biden administration’s focus on Central America and migration from the region, in the wake of a record number of unaccompanied minors who crossed into the US this spring and overwhelmed border facilities.

Harris met with Guatemalan President Alejandro Giammattei on Monday and flew to Mexico to meet with Mexican President Andrés Manuel López Obrador. On Tuesday, Harris said she str