On Dec. 1, Flynn pleaded guilty to making false statements to the FBI about his contacts with Russia's ambassador to the U.S. and agreed to "cooperate fully, truthfully, completely and forthrightly" with the investigation of Russian meddling in the presidential election and whether advisers to Donald Trump were involved in collusion.
A one-page "Joint Status Report" was filed Wednesday in federal court in Washington, D.C., by Mueller's team and Flynn's attorneys. The government was to deliver a status report on Flynn's case to the court Thursday,
"Due to the status of the Special Counsel's investigation, the parties do not believe that this matter is ready to be scheduled for a sentencing hearing at this time," said the document, signed by Mueller, two senior assistants, and Flynn attorneys Robert Kelner and Stephen Anthony.
They said they will give another joint status report in 90 days.
"The parties shall file a joint status report by no later than May 1, 2018, stating whether the matter should be scheduled for sentencing or whether a deadline should be set for filing another joint status report," said a related order signed by Judge Emmet G. Sullivan.
Trusty said Flynn would be "a better witness" if still facing sentencing. Flynn faces up to five years in prison for making false statements to the FBI.
"They don't want to tell the judge to sentence Flynn until they can tell the judge that he helped in the case," he added.
Also on Thursday, three attorneys for former Donald Trump campaign aide, Rick Gates, withdrew from his counsel for reasons that are under seal.
Gates and Paul Manafort, the former chairman of Trump's presidential campaign, both pleaded not guilty to money laundering and other charges filed by Mueller in October.