WASHINGTON — The president’s lawyers have resumed discussions with the office of special counsel Robert Mueller in recent days, the first time that's been acknowledged since President Donald Trump submitted written responses to questions regarding the possibility of collusion between his 2016 campaign and Russia, two people familiar with the matter told NBC News on Thursday.

The president submitted answers to some questions on Nov 20th. At the time, his lawyers said publicly that he would only answer questions regarding the Russia probe and nothing regarding the possibility of obstruction of justice.

The sources would not characterize the nature of the discussions: whether Mueller is pressing for an in-person interview, or how close the process is to wrapping up.

Joyce Vance, a former federal prosecutor and an MSNBC contributor, told NBC news the next logical step for prosecutors would be to focus on two types of further inquiries. The first would be follow-up questions.

"They may ask for clarification or additional information on some of the answers," Vance said.

"The second is they will reopen the conversation about whether the president will submit to an in-person-interview," she added.

When asked about the timing, Vance said: "The timeline makes sense. We're coming into the holidays, they likely don’t want to let it lag for too long. If they want to follow up before the holidays, then this week would be the time to do that."

Jay Sekulow, one of the president’s outside attorneys told NBC News: "We don’t’ discuss conversations we’ve had or have not had with the special counsel.”

Rudy Guiliani, who also represents Trump privately, declined comment.

Chuck Rosenberg a former federal prosecutor who once served as chief of staff to Mueller when he was FBI director said, "it’s not uncommon for the two sides in a big case to be talking all the time."

Trump has repeatedly denied knowledge of any collusion between his campaign and Russia, which interfered with the 2016 election, according to the official U.S. intelligence assessment. The president has also repeatedly referred to the investigation as a "witch hunt."