EAGLE PASS, Texas—State officials here are blocking federal Border Patrol agents from accessing a busy section of the U.S.-Mexico border, the federal government has alleged in a new legal filing, a move that represents an escalation of a standoff between Texas Gov. Greg Abbott, a Republican, and the Biden administration on authority over the U.S.-Mexico border. 

The development comes after state law-enforcement officials in the border town of Eagle Pass took control of the city-owned Shelby Park against the wishes of the city, Mayor Rolando Salinas said on social media Wednesday night. The riverside park, near downtown, is a primary site for city gathering and recreation. It has also become a hot spot for migrants crossing the Rio Grande from neighboring Piedras Negras, Mexico.