WASHINGTON (Reuters) - President Barack Obama and his wife, Michelle, will attend a memorial service in Fort Hood, Texas, on Tuesday for victims of a mass shooting.

The White House announced the trip on Saturday. Obama is scheduled to depart on Wednesday on an Asia tour.

Thirteen people died in the mass shooting Thursday at the sprawling U.S. Army base in Texas. An Army psychiatrist trained to treat war wounded is suspected in the killings.

The suspect, Major Nidal Malik Hasan, a Muslim born in the United States of immigrant parents, was shot four times by police. He was hospitalized and is in stable condition.

Obama devoted his weekly radio address to the Fort Hood shootings, which he called "a crime against our nation."

"It is an act of violence that would have been heartbreaking had it occurred anyplace in America. It is a crime that would have horrified us had its victims been Americans of any background. But it's all the more heartbreaking and all the more despicable because of the place where it occurred and the patriots who were its victims," Obama said.

Hasan, 39, had spent years counseling severely wounded soldiers at the Walter Reed Army Medical Center in Washington, many of whom had lost limbs fighting in Iraq and Afghanistan.

He was transferred to Fort Hood in April and was to have been deployed to Afghanistan, where the U.S. military is engaged in an increasingly bloody war against Taliban and al Qaeda fighters.

(Reporting by Steve Holland, editing by Doina Chiacu)