Navy spokesman Brian O'Rourke says the trial should last about two weeks.
It had been scheduled to start Tuesday, but that date was pushed back after the defense raised concerns that the government's monitoring of its emails to find a news leak had compromised Chief Edward Gallagher's right to a fair trial.
Gallagher's lawyers want the prosecution disqualified and the judge recused if he knew about the scheme.
The judge is expected to discuss his decision at a hearing on Wednesday.
Meanwhile, President Donald Trump said Friday he is considering pardons for several American military members accused of war crimes.
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