A Biden administration effort to reunite children and parents who were separated under President Donald Trump’s zero-tolerance border policy has made increasing progress as it nears the end of its first year.

The Department of Homeland Security is planning to announce that 100 children, mostly from Central America, are back with their families. There have also been about 350 more reunifications.

“I would have loved to have this happen much more quickly. But we are making progress and I feel like we’re gaining momentum,” said Michelle Brane, executive director of the administration’s Family Reunification Task Force.

President Joe Biden issued an executive order on his first day in office to reunite families that were separated under the Trump administration’s widely condemned practice of forcibly separating families and children at the US-Mexico border to discourage illegal immigration.

The work of the task force has been complicated by inadequate or missing records on the separated families, the sheer number of cases and the fact that many parents are in remote Central American communities and were unable to track down their children or get to the United States to retrieve them.

In September, the task force had reunited 50 families when the administration announced a partnership to speed up the effort with the International Organisation For Migration and the creation of a web portal for parents to contact the US government.

About 5,500 children were forcibly removed from their parents under Trump, mostly in 2018, as his administration sought to stop an increase in people crossing the U.S.-Mexico border with criminal prosecutions, even if the migrants were presenting themselves to authorities to seek asylum as permitted under the law.

Amid widespread condemnation, including from Republicans, Trump stopped the practice in June 2018 just days before a judge ordered an end to the programme in response to a lawsuit filed by the American Civil Liberties Union.

Ms Brane said that officials believe there are still about 1,150 children whose whereabouts have not been confirmed.

“Obviously, this is nowhere near the end,” she said. “This is just the beginning of this ramp up and hopefully families will see that reunifications are happening and they will feel confident coming forward.”

Parents and children, including some who arrived at US airports this week, are being granted humanitarian parole to live in the country for a minimum of three years and may pursue permanent status. They are also receiving counselling services.

Hundreds of families have also filed lawsuits against the federal government.

The Justice Department last week told lawyers representing several groups of families that it was withdrawing from settlement negotiations and would defend each case in court.

That came after media reports of a proposed settlement that would include payments of several hundred thousand dollars to each affected person sparked outrage among Biden administration critics in Congress and elsewhere.