Michael Flynn, former U.S. national security adviser, exits federal court in Washington on June 24 ahead of his new attorney, Sidney Powell. (Andrew Harrer/Bloomberg News)

Michael Flynn’s new lawyer told a federal judge Monday that she might not be ready to discuss a sentencing date for President Trump’s former national security adviser for 90 days, and that the defense team wants time to obtain security clearances to access classified information.

Flynn awaits sentencing for lying to the FBI about his Russian contacts in Robert S. Mueller III’s probe of Russian interference in the 2016 election, and his appearance in federal court in Washington was the first since an abortive sentencing hearing in December.

U.S. District Judge Emmet G. Sullivan called for Monday’s hearing after Flynn retained conservative lawyer and commentator Sidney Powell earlier this month as his new counsel and fired his former defense team of Robert K. Kelner and Stephen P. Anthony.

Powell, a former federal prosecutor and critic of Mueller’s investigation, said that Flynn will continue to cooperate with the government, but that she needed time to get up to speed in the case. “There are more moving pieces in this representation than there are movements in an old-fashioned Swiss watch,” she told Sullivan.

Sullivan asked both sides to report back by Aug. 30, sooner than Powell sought, but she agreed, saying she could ask for more time if needed.

Powell said at the hearing that she has received “three hard drives” of material from Flynn’s previous Covington and Burling law firm defense team, with “more to come,” she said. She said without explanation that some information is classified.

U.S. prosecutor Brandon L. Van Grack responded that the government turned over only 20,000 pages of evidence — “not terabytes of information or millions of pages” — and said that the United States had turned over no classified information in its case.

To avoid further delay in Flynn’s sentencing, Van Grack asked that the judge make sure the defense clearance request was necessary.

“You raise a good point,” Sullivan said, directing both sides to confer with a Justice Department classified-information security officer.

Powell confirmed that Flynn is expected to testify at the July federal trial in Alexandria of his former business partner. She and prosecutors Van Grack and Deborah Curtis had asked to update Sullivan about setting a sentencing date afterward, or by mid-August.

Flynn pleaded guilty in December 2017 to lying to the FBI about contacts with then-Ambassador Sergey Kislyak of Russia, becoming one of the first Trump associates to cooperate.

Sullivan opened Monday’s hearing by disclosing that Powell, a white-collar defense appeals specialist and occasional Fox News commentator, sent him a signed copy of her 2014 book titled “Licensed to Lie, Exposing Corruption in the Department of Justice,” which contained praise for Sullivan.

Sullivan said Powell signed his copy “with great respect,” and referred to his role presiding over the bungled corruption trial of then-Sen. Ted Stevens (R-Alaska), lauding Sullivan for unearthing what court-apointed investigator found was “systematic concealment of significant exculpatory evidence” by prosecutors from Stevens.

“In today’s day and age, I think I should put it into the record,” Sullivan said, in case there were concerns about bias, adding, “If anyone has any problems, speak now.” No one in court did.

After his December 2017 plea, Flynn agreed to cooperate in Mueller’s investigation, leading to his sentencing being delayed to December 2018.

Sullivan postponed sentencing at that time after lambasting the former three-star general and his lawyers for suggesting that the FBI had duped Flynn. “Arguably, you sold your country out,” Sullivan told Flynn at the time.

Flynn then asked that his sentencing be postponed, promising to continue cooperating with the government.

There was no hint of awkwardness at Monday’s hearing, with the judge starting by saying, “Mr. Flynn, how are you?” and Flynn answering with a hearty “Great!”

Flynn, Powell and co-defense attorneys Jesse R. Binnall and W. William Hodes left the courthouse without commenting.