Army Sgt. Bowe Bergdahl leaves the courthouse after the first day of sentencing proceedings in his court-martial at Fort Bragg, N.C. (Jonathan Drake/Reuters)

The military judge who will decide whether Sgt. Bowe Bergdahl goes to prison for leaving his post in Afghanistan indicated Monday that President Trump's recent remarks on the case could raise doubts about the Army sergeant's legal proceedings and whether they were fair.

Bergdahl, 31, faces life in prison. He said few words during the first day of his presentencing hearing, having pleaded guilty to charges of desertion and misbehavior before the enemy in connection with his 2009 disappearance and five-year captivity by a Taliban affiliate.

But the court heard several sound bites from Trump as the judge, Army Col. Jeffrey R. Nance, sought to determine whether the president's new comments affirmed his past statements about Bergdahl being a "dirty, rotten traitor."

Speaking to reporters last week, Trump declined to say whether his previous attacks on Bergdahl may have unfairly influenced the soldier's decision to plead guilty. Yet his word choice — "But I think people have heard my comments in the past," the president said — was the subject of debate between Nance and attorneys for the defense and prosecution. In 2015, Trump also promised to review decisions made in the case if he were to become commander in chief.

A military judge to decide if Bowe Bergdahl should be jailed for life

Lead defense attorney Eugene Fidell filed a motion saying Trump's latest comments build on his harsh campaign rhetoric and amount to unlawful command influence, thus compromising Bergdahl's chances to receive a fair sentencing. The motion seeks to dismiss the case on those grounds.

Trump's comments reconfirmed his past statements and produced a "chilling effect" on the military justice system, Fidell said — to such a degree that Nance should not impose jail time for Bergdahl.

"Words have meaning. And 'but' means what?" Nance asked prosecutor Maj. Justin Oshana, who disputed Fidell's assertion that Trump continues to hold such views about Bergdahl.

Nance challenged Oshana for much of the presentencing hearing, which lasted an hour and concluded with a recess until Wednesday.

Nance had ruled in February that Trump's campaign remarks, while "disturbing," did not amount to unlawful command influence. But he appears to be reconsidering.

"The reasons [to dismiss earlier accusations] tend to be eroded when the now-president of the United States apparently adopts those past statements," Nance told the prosecutor. Nance added his interpretation of Trump's meaning to be: "I shouldn't comment on that, but I think everyone knows what I think on Bowe Bergdahl."

Pressed further on Trump's verbiage, Oshana offered that the president's words were "not the best constructed," a statement that elicited stifled chuckles in the courtroom.

Nance said he purposely avoided media reports about Bergdahl's case, adding, "I don't have any doubt whatsoever I can be fair and impartial in this sentencing." He intends to retire soon, he noted, and is not slated for a promotion, suggesting commanders had little leverage to pressure him to enforce a harsher penalty.

Oshana pointed to a White House statement issued Friday that he characterized as evidence Trump has not sought to influence what punishment Bergdahl receives.

"The President expects all military personnel who are involved in any way in the military justice process to exercise their independent professional judgment, consistent with applicable laws and regulations," the statement says. It does not mention Bergdahl by name, however.

Bergdahl entered a guilty plea last week to charges of desertion and misbehavior before the enemy, the second of which carries the possibility of a life sentence. He declined an opportunity Monday to withdraw those pleas.

He vanished from his remote base in Afghanistan in 2009 and was captured by the Taliban, at whose hands he endured five years of brutal captivity before he was handed over in a controversial prisoner swap in 2014, in which five Taliban militants also were freed.

Nance is expected to rule this week on Bergdahl's motion to dismiss the case. There will be no court activity Tuesday or Friday, raising the possibility that his decision on Bergdahl's fate will come next week.

Prosecutors are expected this week to use testimony from troops who have said they were injured on recovery missions after Bergdahl walked off his outpost in rugged Paktika province. Attempts to find him involved thousands of troops and diverted resources such as surveillance drones and helicopters as ground troops scoured the area for weeks.

Nance has ruled previously that a Navy SEAL and an Army National Guard sergeant were wounded in firefights that probably would not have happened if Bergdahl had not disappeared.