President Obama and first lady Michelle Obama will attend a memorial service in Texas Wednesday for the victims of last week's mass shooting at Fort Hood.

Dan Pfeiffer, a senior White House aide, confirmed Sunday that the Obamas would attend the memorial service.

"It's a terrible tragedy that happened in Fort Hood. The president and the first lady send their thoughts and prayers out to the victims and families and everyone on the base.  And they're going to actually travel down on Wednesday to the memorials," Pfeiffer said on CBS's "Face the Nation."

A spontaneous argument among soldiers in the same transportation unit at Fort Hood touched off the mass shooting in which Spec. Ivan A. Lopez killed four people, including himself, and wounded 16 others, Army officials said Friday.

The Obamas are already scheduled to be in Texas this week to attend Democratic Party fundraisers in Houston, and the president also is scheduled to speak at a civil rights summit at the LBJ Presidential Library in Austin to commemorate the 50th anniversary of the signing of the Civil Rights Act.

Obama last visited Fort Hood in November 2009 to speak at a memorial service for the 13 killed and dozens injured during a similar mass shooting at the base. Maj. Nidal Hasan was convicted last August for those killings.

On Sunday, Rep. Michael McCaul (R-Tex.), chairman of the House Homeland Security Committee, suggested that Congress should consider lifting the ban on service members carrying weapons on military bases.

While the ideal situation would be to hire more military police officers to protect military installations, "in the current budget climate, that's not as realistic," McCaul said in a separate appearance on "Face the Nation." "So it seems to me a force multiplier of officers and enlisted men that we can trust the senior leadership to have them carry. Because, you know, it only takes a few minutes to wound and kill a large number of soldiers. Any time we see soldier-on-soldier, it's one of the most tragic things we can conceive. And if we had senior leadership armed, just maybe they could have stopped it before it got worse."