A federal judge on Wednesday delayed the sentencing date for Michael Flynn, President Donald Trump's first national security adviser.

Flynn was to be sentenced Dec. 18, but his lawyers and federal prosecutors asked for a delay. They said a report from the Justice Department's inspector general examining aspects of the FBI's investigation of the Trump campaign, due out Dec. 9, could contain material relevant to the sentencing. They also said the judge has yet to rule on a dispute between the prosecutors and Flynn's lawyers over the government's production of documents that the defense said could have affected Flynn's decision to plead guilty.

Flynn entered his plea two years ago to a single charge of lying to the FBI. He admitted that four days into his job as White House national security adviser, he falsely denied having two separate contacts during the Trump transition with Russia's ambassador to the U.S., Sergey Kislyak.

In return for what he hoped would be a lenient sentence of no jail time, he agreed to help members of special counsel Robert Mueller's team with their investigations. But at a sentencing hearing last year, federal District Court Judge Emmet Sullivan was harshly critical of Flynn's conduct, including his failure to disclose lobbying work for the government of Turkey.

"Arguably, you sold your country out," Sullivan said. The judge agreed to delay the sentencing and urged Flynn to try harder to cooperate with prosecutors.

After that disastrous court appearance, Flynn brought in a new team of lawyers who mounted a vigorous attack on every aspect of the government's conduct in investigating and prosecuting him — most recently accusing prosecutors of withholding potentially helpful documents. In response, Justice Department lawyers said Flynn's lawyers relied on "conspiracy theories, demanding that the government engage in a fishing expedition for documents that could offer support for those theories."

But Flynn's lawyers have not suggested he is considering withdrawing his guilty plea.

In agreeing to cancel the Dec. 18 sentencing date, Judge Sullivan did not indicate when he would schedule a new sentencing hearing.