The trial of a decorated Navy SEAL charged with killing an Islamic State prisoner in his care is set to begin with jury selection on Monday.

The politically charged case has included the removal of the lead prosecutor for tracking the defense team's emails and suggestions by President Donald Trump that he may pardon the defendant.

Special Operations Chief Edward Gallagher has pleaded not guilty to premeditated murder in the killing of an Islamic State prisoner in his care and attempted murder in the shootings of two Iraqi civilians in 2017.

A Navy judge ruled the prosecution's effort to track defense emails violated Gallagher's constitutional rights against illegal searches and the right to counsel by interfering with attorney-client privilege.

He is allowing the defense to reject two more potential jurors without cause than usual during jury selection.