The United States is mourning the deaths of six people in a shooting in Arizona on Saturday which left a congresswoman seriously wounded.
Flags across the country are flying at half mast. President Barack Obama led a minute's silence at 11am (EST) on Monday on the South Lawn of the White House.
"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 in a statement on Sunday.
House of Representatives Speak John Boehner called on fellow legislators to "stand together" and "rally round our wounded colleague".
The man charged with the attack, Jared Loughner, 22, is due to appear in court in Phoenix at 2pm MST (4pm EST, 2100 GMT) on Monday.
Congresswoman Gabrielle Giffords was shot in the head and is in a critical condition, but the hospital says responding to simple commands.
She had been holding an open-invitation meeting with constituents outside a supermarket in Tucson on Saturday afternoon when a man holding a gun approached and opened fire.
Ms Giffords, 40, was shot from close range by the gunman, who then began shooting into the crowd.
Among the dead were a girl and a federal judge. A total of 14 people were wounded, in addition to the six who were killed.
The girl, Christina Taylor Green, aged nine, was born on 9/11.
