(CNN) - Paul Manafort's lawyers said Tuesday they are not sure if they will challenge Robert Mueller's assertion that Manafort lied in interviews when he was supposed to be cooperating with the special counsel.
The defense team has until the first week of January to decide their strategy, Judge Amy Berman Jackson said in a court hearing Tuesday. A hearing on the facts of the breach of the plea agreement -- at which Mueller's team could call witnesses and present evidence -- is now scheduled for January 25.
Tuesday's hearing was the first since Mueller's team revealed Friday that they believe former Trump campaign chairman Manafort lied about five major issues after he pleaded guilty and began cooperate with prosecutors. His lies included a cover up about his "contact with administration officials," Mueller's team said.
In a heavily redacted document, Mueller also said Manafort lied about his interactions with Konstantin Kilimnik. Mueller has said Kilimnik has ties to the Russian military intelligence unit accused of hacking the Democrats, and they've previously outlined how the two men may have worked together to tamper with witnesses following Manafort's arrest last year.
Jackson responded Tuesday by asking Mueller's team for more evidence and details about why it believes Manafort lied. That, too, will be put off until the new year, keeping more information about how Manafort's cooperation fell through and what Mueller is investigating secret even longer. Some of the details in Friday's filing were not made public because they could reveal ongoing investigations and people who haven't yet been charged with crimes, the special counsel's office said.
For now, Manafort's lawyers and prosecutors are negotiating behind the scenes about what might happen next.
"There is some sense today the certainty of a hearing is less clear," defense attorney Richard Westling said. "Does it make sense to put the court through that?"
Manafort did not attend the hearing. He was last seen in public in a Virginia courtroom in October, with a foot bandaged and using a wheelchair because of a medical condition similar to gout.
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