The policy forced non-Mexican migrants to stay in Mexico until their immigration court date in the US. It was suspended at the beginning of President Joe Biden's term and formally terminated months later. But in August, a federal judge in Texas said that the Biden administration had violated federal law in how it went about unwinding the program and required it be restored.

Friday, the Department of Homeland Security will release a new memo justifying its desire to end the policy, formally known as the Migrant Protection Protocols, DHS officials say.

Under President Donald Trump, migrants from Central America and other parts of the world who were seeking asylum at the US-Mexico border were forced to stay in Mexico until their immigration court hearings in the US, often in dangerous cities. It marked an unprecedented departure from previous protocols, which had allowed for the entry of migrants as they went through their immigration hearings in the United States.

An estimated 68,000 migrants were returned to Mexico under the policy, according to the Department of Homeland Security. For those subject to the policy, that meant waiting months, if not years, in squalid conditions and under the threat of extortion, sexual assault and kidnapping.

"MPP had endemic flaws, imposed unjustifiable human costs, pulled resources and personnel away from other priority efforts, and did not address the root causes of irregular migration," Homeland Security Secretary Alejandro Mayorkas said in a statement.

The Biden administration has faced fierce criticism from allies for keeping some of Trump's immigration limits in effect. After additional review of the Remain in Mexico policy, DHS found that while it may have led to a reduction in border crossings, the humanitarian costs justify its termination.

"It delves much deeper into the decision-making and the reasoning behind the decision," a Homeland Security official told reporters, referring to the new memo. "It squarely addresses some of the alleged failures of the prior memo, as well -- addressing the alleged costs to states and alleged concerns about the implications of terminating [Migrant Protection Protocols]."

The new memo cannot take effect until the court order has been lifted.

The future of the program has been a point of discussion between the US and Mexico, according to officials, specifically ensuring that cases are heard in a timely manner, that migrants have access to counsel, and establishing criteria for those who aren't subject to the policy.

DHS previously said it's updating policies and procedures to account for Covid-19 and preparing contracts to rebuild the soft-sided immigration hearing facilities that came under intense scrutiny during the Trump administration. According to another Homeland Security official, the administration is considering vaccinating and testing migrants subject to the program for Covid-19, as well as assessing whether there are shelters people can safely stay in until their court date.

The administration also sent out notices to legal service providers to be included on a pro bono list to be distributed to migrants enrolled in the "remain in Mexico" program, according to an email obtained by CNN.

But immigrant advocates and attorneys say they're not interested in associating themselves with a policy they condemned under the Trump administration. Elissa Steglich, who co-directs and teaches the Immigration Clinic at the University of Texas at Austin, cited the challenges in representing migrants waiting in Mexico and the slew of due process and security concerns.

"We cannot support participating in a list that makes it appear that the program promises access to counsel," Steglich said.