TACOMA, Wash. -- A Fort Lewis officer who is planning to disobey an Army order to go to Iraq called the war "horribly wrong" and "manifestly illegal" in a videotape shown at a news conference in Tacoma on Wednesday.

Lt. Ehren Watada received written orders on Tuesday not to attend meetings or press conferences during working hours, so his videotaped statement was played instead.

Watada said it's his duty as a commissioned officer to speak out against what he calls a "grave injustice." He said his obligation is to the Constitution and not to what he regards as illegal orders.

"The wholesale slaughter and mistreatment of the Iraq people with only limited accountability is not only a terrible moral injustice, but a contradiction to the Army's own Law of Land Warfare," he said in the statement.

The statement was released by friends and supporters, many wearing shirts bearing messages that included "Veterans for Peace" and "Military Families Speak Out."

Supporters said Watada would appear in person at a news conference at 6 p.m. in Tacoma.

The 29-year-old from Honolulu is a member of a Stryker brigade being deployed this month to Iraq.

Watada is not a conscientious objector. He said he's not against all war, only Iraq. He said the military would not reassign him or let him resign his commission.