U.S. Navy Secretary Richard Spencer said on Friday a navy SEAL convicted of battlefield misconduct should face a board of peers weighing whether to oust him from the elite force, despite President Donald Trump's assertion that he not be expelled.

"I believe the process matters for good order and discipline," Spencer said, weighing in on a confrontation between Trump and senior navy officials over the outcome of a high-profile war-crimes case.

A military jury in July convicted Special Operations Chief Edward Gallagher of illegally posing for pictures with the corpse of an Islamic State fighter but acquitted him of murder in the detainee's death. Gallagher also was cleared of charges that he deliberately fired on unarmed civilians.