President Biden announced that his administration will extend a pause on federal student loan payments while the White House fights a legal battle to save his plan to cancel portions of the debt.

“It isn’t fair to ask tens of millions of borrowers eligible for relief to resume their student debt payments while the courts consider the lawsuit,” Mr. Biden said in a video posted Tuesday on Twitter.

Mr. Biden has pledged to end the moratorium January 1. Tuesday’s reversal means the moratorium has been extended eight times. Now it will extend until 60 days after the lawsuit is resolved. If the lawsuit has not been resolved by June 30, payments would resume 60 days after that.

Extending the moratorium through the end of August 2023 will cost taxpayers an additional $40 billion, according to the Committee for a Responsible Federal Budget, bringing the total cost of the pause to at least $195 billion. Unlike the forgiveness plan, which is limited to low- and middle-income borrowers, the moratorium applies to payments by all Americans no matter their income.

The Biden administration didn’t address the costs in its announcement, but instead sought to cast blame on Republicans for challenging the plan.

“Callous efforts to block student debt relief in the courts have caused tremendous financial uncertainty for millions of borrowers who cannot set their family budgets or even plan for the holidays without a clear picture of their student debt obligations,” the education secretary, Miguel Cardona, said.

More than 26 million people already applied for the relief, with 16 million approved, but the education department stopped processing applications this month after a federal judge in Texas struck down the plan.

The justice department last week asked the Supreme Court to examine the issue and to reinstate Mr. Biden’s debt cancellation plan. By extending the pause, the administration says it’s giving the court a chance to resolve the case in its current term.

Mr. Biden announced the decision a day after more than 200 advocacy groups urged him to extend the pause, warning that starting payment in January would cause “financial catastrophe” for millions of borrowers.

The White House has argued in court that Americans continue to feel the financial stress of the Covid pandemic. Without Mr. Biden’s cancellation plan, it says, the number of people falling behind on student loan payments could rise to historic levels.

The greatest risk is for about 18 million borrowers who were told their entire loan balance would be canceled. Even if payments restart, those borrowers might think they’re in the clear and ignore the bills, the education department has warned.

The legality of broad student debt cancellation has been in question since before Mr. Biden took office. Supporters say federal law already gives the education department wide flexibility to cancel student loans, while opponents argue that only Congress has the power to cancel debt at that scale.

In announcing its plan, the Biden administration invoked the Heroes Act of 2003, a post-September 11, 2001, law meant to help members of the military. The justice department says the law offers sweeping authority to cancel student debt during a national emergency such as the Covid pandemic.

A federal judge in Texas struck down that rationale this month, saying Mr. Biden overstepped his power. The Heroes Act “does not provide the executive branch clear congressional authorization to create a $400 billion student loan forgiveness program,” a district court judge, Mark Pittman, wrote.

The Justice Department is asking an appeals court in New Orleans to suspend Judge Pittman’s order while the administration appeals. It’s separately asking the Supreme Court to overrule a federal court in St. Louis that halted Mr. Biden’s plan in response to a lawsuit from six Republican-led states.