Washington, Jan 21 (IANS): US Army Sergeant Bowe Bergdahl, charged with desertion in Afghanistan, wants a case against him dismissed, saying he cannot get a fair trial now that Donald Trump, who has called him "dirty rotten traitor", is President, the media reported.

Bergdahl lawyers submitted the motion on the day that Trump took the oath of office as 45th US President in Washington, Politico reported on Friday.

Trump is now the Commander in chief, giving him direct authority over the judge assigned to Bergdahl's cases as well as the service members selected to serve on his court-martial.

Bergdahl's attorneys say Trump's rhetoric and his new military role inevitably create "unlawful command influence" that has eliminated any possibility that their client can get a fair shake in the military justice system.

"President Trump has made it impossible for SGT Bergdahl to obtain a fair trial," Bergdahl's lawyers wrote in the motion. "President Trump transformed his rallies into a televised travelling lynch mob. Justice cannot be done and public confidence in military justice cannot be maintained under these circumstances."

Trump pilloried Bergdahl on more than 40 occasions during the presidential campaign, often blasting Bergdahl as a traitor who deserved to be executed.

As a candidate, Trump sometimes "pantomimed executions by rifle and pistol shot, complete with sound effects." The defence sent the judge a video splicing together many of the comments and the visuals.

Bergdahl's legal team was also raising the possibility of calling Trump as a witness, if military prosecutors are unwilling to agree to the accuracy of the videos and news reports depicting Trump's comments.

Bergdahl went missing from his base in Afghanistan in 2009. He spent five years as a prisoner of the Taliban before being released in a prisoner swap negotiated by the Obama administration, involving the release of five Taliban fighters long held at Guantánamo Bay.

Trump was among many Republicans who denounced the trade as unwise and who questioned Bergdahl's loyalty to the US.

In 2015, Bergdahl was charged with desertion and misbehaviour before the enemy. A military lawyer who conducted a preliminary hearing recommended that Bergdahl be sent to a special court-martial and receive no jail time, but an Army general ordered that the soldier face a general court-martial on the two serious charges, with a possible sentence of up to life in prison.