Obama to Lead Moment of Silence After Shooting Targeting Ariz. Congresswoman

Jan. 5: Rep. Gabrielle Giffords, D-Ariz., takes part in a reenactment of her swearing-in, on Capitol Hill in Washington. (AP)

When President Barack Obama steps out on the South Lawn of the White House Monday morning, the thoughts of the nation will turn to Arizona Rep. Gabrielle Giffords and the other victims of an assassination attempt against her.

Obama will lead the nation in a moment of silence to honor the congresswoman and the six people killed and 14 wounded in Saturday's shooting outside a Tucson supermarket.

"It will be a time for us to come together as a nation in prayer or reflection, keeping the victims and their families closely at heart," he said Sunday in a statement.

The Supreme Court plans to convene early so the justices can observe the moment of silence.

Giffords, 40, remained in intensive care at a Tucson hospital after being shot in the head at close range. Among those killed were Arizona's chief federal judge, a 9-year-old girl interested in government, and one of Giffords' aides.

"Gabby was doing what she loved most -- hearing from her constituents -- when this tragedy occurred. Serving Southern Arizonans is her passion, and nothing makes her more proud than representing them in Congress," astronaut Mark Kelly, Giffords' husband, said in a statement issued late Sunday.

"We must never forget [the victims], and our prayers are with their families. Our hearts go out to everyone injured yesterday; we hope and pray for their quick recovery," Kelly said.

Prosecutors charged 22-year-old Jared Loughner with one count of attempted assassination of a member of Congress, two counts of killing an employee of the federal government and two counts of attempting to kill a federal employee. More charges are expected.

House Speaker John Boehner told lawmakers in a conference call Sunday to "pull together as an institution."

"What is critical is that we stand together at this dark time as one body," he said. "We need to rally around our wounded colleague, the families of the fallen and the people of Arizona's 8th District. And, frankly, we need to rally around each other."

Giffords, a Democrat, represents Arizona's 8th District.

House business this week, including a contentious vote scheduled for Wednesday to repeal Obama's new health care law, has been postponed to focus on any necessary actions in the shooting aftermath.

Connecticut Rep. John Larson, who heads the House Democratic Caucus, said Sunday that lawmakers will continue to have open sessions with their constituents, although they are likely to take more precautions.

The chief law enforcement official in the House, Sergeant-at-Arms Bill Livingood, is holding a conference call Monday with House members to discuss security.

The Associated Press contributed to this report.