WASHINGTON (AP) — The top White House lawyer will leave next month after a nearly three-year run helping President Joe Biden weigh legal considerations as he implemented his pandemic response, battled Republican investigations and crafted major legislation.

Stuart Delery joined Biden's transition legal team after the Democrat defeated then-President Donald Trump in November 2020. Delery served as deputy counsel before he was elevated to the top job last summer after Biden's first counsel, Dana Remus, left the White House.

Delery is the first openly gay person to be White House counsel.

Biden, in a statement Thursday, called Delery “a trusted adviser and a constant source of innovative legal thinking. ... He has been an integral part of my team."

The White House has not announced Delery's successor.

Delery's departure comes as House Republicans investigate Biden's son Hunter as well as the origins of COVID-19. Some GOP lawmakers are pressing for an impeachment inquiry into the president. Meantime, a special counsel named by Biden's attorney general is investigating the presence of classified documents at Biden’s Delaware home and former Washington office.

The White House has about two dozen legal, legislative, and communications aides working on oversight and investigations. Biden's personal lawyer, Bob Bauer, is handling the classified documents matter.

Biden's chief of staff, Jeff Zients, has asked Cabinet members and senior officials to decide by the end of summer whether they will leave or stay on the job through 2024 and the election. A White House official, who was not authorized to comment publicly and spoke on condition of anonymity, said Delery's departure had been long planned.

“You need to be able to give your successor a runway and the reason to want to be your successor,” said Susan Rice, a former domestic policy adviser in the Biden administration who worked closely with Delery before she left the White House earlier this year. “So I don’t think that this should be in any way construed as bad timing or the consequence of any exogenous factors.”

Rice, who also held senior roles in the Clinton and Obama administrations, described Delery as “unflappable."

“I have never seen him lose his temper or his cool. I’ve never seen him get irritable with anybody, which is unbelievable,” Rice said.

She added: “None of us are irreplaceable but there are few people who have been around as long as Stuart, who have the knowledge, experience, and the confidence of colleagues and the president that Stewart has. It’s a loss, big time.”

As deputy counsel, Delery played a critical role in advising Biden on key legislation, including the $1.9 trillion American Rescue Plan aimed at helping the country climb out of he coronavirus crisis and the $1 trillion infrastructure bill.

As the chief White House lawyer, Delery was a top adviser as Biden crafted a student loan forgiveness order last year aimed at canceling $400 billion in debt for borrowers. The Supreme Court, in a 6-3 decision with conservative justices in the majority, said the administration overstepped its authority with the plan, and it left borrowers on the hook for repayments that are expected to resume in the fall.

The White House unsuccessfully argued it had legal authority to cancel debt through a law that enabled the education secretary to “waive or modify any statutory or regulatory provision” and was later altered to include people affected by “a war or other military operation or national emergency.” The White House said the COVID-19 pandemic qualified as such an emergency.

Biden introduced a more modest plan last month to provide some relief for those with college debt. The new proposal is using a federal law that governs the student loan program as the legal underpinning. That law includes a provision giving the education secretary authority to “compromise, waive or release” student loans.

The new plan is also facing a legal challenge.

Delery also played a key role in helping the administration put new rules into place at the U.S. -Mexico border to try to to stop migrants from crossing illegally and encourage them instead to apply for asylum online through a new process.

The changes came with the end of coronavirus restrictions on asylum implemented during the pandemic health emergency. The restrictions, imposed under the authority of Title 42 of a 1944 public health law, allowed curbs on migration in the name of protecting public health.