US President Barack Obama said the United States was failing to keep its children safe, with the country facing no other choice but to change.
Speaking during a vigil for the victims of the school shooting in Newtown in Connecticut Mr Obama said there had to be an end to such tragedies, as he pledged to take action.
The massacre of 26 children and adults at Sandy Hook Elementary on Friday provoked horror around the world, soul-searching in the United States and fresh political debate about gun control.
Members of the audience wept when the president read out the names of the children whio were shot.
The president first met privately with families of the victims and with the emergency services who responded to the shootings.
A more detailed picture of gunman Adam Lanza's attack has emerged:
- Lanza was carrying an arsenal of hundreds of rounds of ammunition
- If given enough time it was enough to kill just about every student in the school
- He used used a Bushmaster AR-15 type weapon
- The weapon is highly modular, meaning a user can change the barrel, the stock and other features, easily changing a weapon's characteristics such as weight, capacity, range and accuracy
- He also had two handguns which he carried into the school, and had a fourth weapon, a shotgun, in his car outside