A U.S. Army appeals court has ruled that Fort Hood shooting suspect Major Nidal Hassan must shave off his beard for trial.

The court on Thursday rejected Hassan's argument that his beard is an expression of his Muslim faith. It ordered him to shave it off or have it removed by force.

Hasan, an Army psychiatrist, is accused of killing 13 people and wounding 32 others when he opened fire at Fort Hood, Texas in November 2009.

The survivors and victims' families want the Obama administration to classify the attack as an act of terrorism so their benefits can be increased. Service members who were wounded or killed would also be eligible to receive the military's Purple Heart medal.