The White House said Tuesday it will limit work permits for undocumented immigrants brought to the United States as children to one year instead of two, as administration officials reconsider whether to terminate an eight-year-old program that protects such immigrants from deportation.

The move comes more than a month after the U.S. Supreme Court ruled 5 to 4 that the Trump administration could not carry out its plans to end the Obama-era program known as Deferred Action for Childhood Arrivals, or DACA, because it had not provided proper legal justification for terminating it.

A White House official, speaking on the condition of anonymity, said Tuesday that the administration decided to shorten the work permits as it undertakes the legal review the court said was lacking when officials announced in late 2017 that they would phase out the program by this year. The official declined to say how long the review would take.

Acting Department of Homeland Security Secretary Chad Wolf published a memo on Tuesday limiting the work permits and signaling that DACA “presents serious policy concerns that may warrant its full rescission.” He said he would continue to bar new applications.

DACA has provided two-year, renewable work permits and protection from deportation to as many as 800,000 undocumented immigrants brought to the United States as children since the program began in 2012. Applicants must have lived in the United States for several years, attended school, and pass a background check, among other requirements. Approximately 640,000 people remain in the program, and many are health-care workers, teachers and emergency responders.

In the memo, Wolf said cutting the work permits’ validity in half “will have the potential benefit of significantly lessening the lasting effects of the DACA policy if I ultimately decide to rescind it.”

Advocates for immigrants had hoped the court’s June 18 ruling would fully restore the DACA program, including for tens of thousands of potential new applicants who are currently not allowed to apply.

California Attorney General Xavier Becerra, whose office led one of the legal challenges against ending DACA, signaled that he would challenge the new policy in court. He said DACA should be “in full effect, including for new applications.”

“The courts have spoken,” he said. “We know what it takes to defend DACA . . . and we’ll do it again if necessary.”

The White House’s announcement follows weeks of uncertainty and conflicting signals from President Trump. Trump had earlier indicated that he would sign an immigration bill that would include DACA.

The White House’s move also backs away from one of Trump’s key campaign promises — to end a program he called an “illegal amnesty” on the campaign trail — as he is behind Democratic candidate Joe Biden in the polls, struggling with a rising novel coronavirus death toll and engaging in fiery battles with demonstrators in Portland, Ore.

Biden, who was vice president when President Barack Obama created the program, supports DACA.