(CNN) -- The Justice Department formally rescinded the Trump administration's controversial "zero tolerance" policy that called for the criminal prosecution of adults crossing the border and led to the separation of thousands of families, according to a memo obtained by CNN.
The policy was ended by former President Donald Trump in June 2018 after mounting criticism, but on Tuesday, the department moved to rescind it altogether.
"Consistent with this longstanding principle of making individualized assessments in criminal cases, I am rescinding -- effective immediately -- the policy directive," acting Attorney General Monty Wilkinson said in a memo to federal prosecutors.
"While policies may change, our mission always remains the same: to seek justice under the law," Wilkinson added.
The Associated Press first reported on the memo.
Lawyers are still unable to reach the parents of 611 children who had been split from their families by US border officials between 2017 and 2018, according to the latest court filing.
President Joe Biden has pledged to undo Trump's policies and on Friday is expected to announce a task force that will focus on reuniting separated families.
In a statement to CNN, a Justice Department spokeswoman called the "zero tolerance" policy "inconsistent with the Department's longstanding principle that we exercise judgment and make individualized assessments in criminal cases."
"Today's action restores to prosecutors their traditional discretion to make charging decisions based on a careful review of the particular facts and circumstances of individual immigration cases," the spokeswoman said.
The policy had long-term ramifications for the thousands of families it affected.
Since the policy ended, a series of government watchdog reports have detailed the disarray within agencies when the policy was implemented, the lack of planning, and trauma it inflicted on the children separated from their parents.
Earlier this month, the Justice Department's inspector general revealed that former Attorney General Jeff Sessions knew early on migrant families would be separated when the Trump administration implemented the policy and proceeded with it anyway.
"[T]he Department's single-minded focus on increasing prosecutions came at the expense of careful and appropriate consideration of the impact that prosecution of family unit adults and family separations would have on children traveling with them and the government's ability to later reunite the children with their parents," the IG report stated.
This story has been updated with additional details of the zero tolerance policy.