WASHINGTON — The American Civil Liberties Union and other advocacy groups said Monday that they were ending settlement talks with the Biden administration over their demand to lift a pandemic-related ban on families seeking asylum in the United States.

The impasse resumes a legal battle before U.S. District Judge Emmet Sullivan in Washington over emergency powers to expel migrants without a chance to seek asylum on grounds it prevents spread of the coronavirus. Under Title 42 authority, named for a 1944 public health law, the administration has banned many families and nearly all single adults from seeking asylum. Unaccompanied children have been exempted.

“We are deeply disappointed that the Biden administration has abandoned its promise of fair and humane treatment for families seeking safety, leaving us no choice but to resume litigation,” said Neela Chakravartula, managing attorney for the Center for Gender & Refugee Studies.

Since late March, the ACLU has been working with advocates across the border to submit names of particularly vulnerable migrants stuck in Mexico to U.S. authorities, allowing them in the United States to seek asylum. ACLU attorney Lee Gelernt said the exemptions will continue another week.

“Seven months of waiting for the Biden administration to end Title 42 is more than enough,” Gelernt said.

The Homeland Security and Justice departments did not immediately respond to a request for comment.

The breakdown reflects growing tensions between immigrant advocates and the administration over use of Title 42 authority and the government’s decision last week to resume fast-track deportation flights for families to Guatemala, El Salvador and Honduras.

Last week, the International Rescue Committee said they were ending efforts to help the administration exempt asylum-seekers from the pandemic-related ban. The groups had been working on a parallel track with the ACLU to identify particularly vulnerable migrants stuck in Mexico.