The lawsuit has not moved forward as the sides negotiate, Mr. Gelernt said.
In an attempt to limit the spread of the coronavirus, Title 42 allows the United States to immediately send migrants back across the border even if they wish to make an asylum claim. It is the main border policy from the Trump era that the Biden administration kept in place, although the current administration has exempted all minors who are traveling alone.
But thousands of families that Mexico would not allow to re-enter have been processed by the U.S. Border Patrol and released to shelters with notices to check in with Immigration and Customs Enforcement or to appear in immigration court for a hearing. They are allowed to live in the interior of the country while their cases are adjudicated.
Advocates have been hoping that the C.D.C. would revoke Title 42, which they consider a tool used for immigration enforcement rather than for protecting the country from the virus. Critics say that quick deportations are especially problematic because they can lead to erroneous expulsions.
“The announcement we had been hoping for was about an end to Title 42,” said Linda Rivas, the executive director of Las Americas Immigrant Advocacy Center in El Paso, Texas. She added, “This administration continues to seek efficiency over safety and due process for migrant families.”
As coronavirus infections from the highly contagious Delta variant started to rise, administration officials and border officials began expressing concern that eliminating the public health order would encourage more migrants to make their way to the border.
In June, Border Patrol agents encountered 188,800 people, the highest monthly number in at least a decade. That brought to one million the number of border apprehensions in the first nine months of the fiscal year, which ends Sept. 30.
Agents apprehended 55,805 family members and 15,253 unaccompanied minors in June, up from 44,639 and 14,158 in May. Just 14 percent of the families intercepted last month were expelled under the public health order.