WASHINGTON (AP) -- President Bush said Monday that the mass shooting at Virginia Tech, the deadliest campus violence ever in this country, affects every student across the nation.

"Schools should be places of safety, sanctuary and learning," Bush said in reaction to the deaths of more than 30 people on the campus. "When that sanctuary is violated, the impact is felt in every American classroom in every American community."

Bush spoke with Gov. Timothy M. Kaine and Virginia Tech President Charles Steger. (Watch what Bush pledged to do to help the investigation http://i.a.cnn.net/cnn/.element/img/1.5/main/icon_video.gif)

"I told them that Laura and I and many across our nation are praying for the victims and all the members of university community that have been devastated by this terrible tragedy," Bush said in the Diplomatic Room of the White House.

"Today our nation grieves with those who have lost loved ones at Virginia Tech," he said. "We hold the victims in our hearts. We lift them up in our prayers and we ask a loving God to comfort those who are suffering today."'

Attorney General Alberto Gonzales said agents from the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives were already on the campus, aiding local authorities in the investigation.

"We are committed to providing support and assistance to those authorities as well as to the victims of this crime for as long as necessary," Gonzales said in a statement issued by the Justice Department.

"I am deeply saddened and angered by these senseless acts of violence," Gonzales said. "My deepest condolences and prayers go out to those affected by this horrific crime, especially those who lost loved ones."

Gonzales had been scheduled to testify before the Senate Judiciary Committee Tuesday regarding the firing of eight U.S. attorneys, but that testimony was postponed because of the Virginia shootings.

In the House, which returned Monday from a two-week recess, Speaker Nancy Pelosi, D-California, interrupted the proceedings to lead a moment of silence in remembrance. (Watch Speaker Pelosi express Congress' sympathy for the shooting victims http://i.a.cnn.net/cnn/.element/img/1.5/main/icon_video.gif)

"As the Virginia Tech community struggles with the mourning and questioning that is certain to follow, the continued prayers from this Congress are with the students, their families, the faculty and the staff at Virginia Tech," Pelosi said.