The powerful US gun rights lobby has gone on the offensive arguing that schools should have armed guards, on a day that Americans remembered the victims of the Connecticut school massacre with a moment of silence.
"The only thing that stops a bad guy with a gun is a good guy with a gun," said Wayne LaPierre, chief executive of the National Rifle Association.
He noted that banks and airports are patrolled by armed guards, while schools typically are not.
His remarks - in which he charged that the news media and violent video games shared blame for the second-deadliest school shooting in US history - were twice interrupted by protesters who unfurled signs and shouted "stop the killing”.
Speaking in Washington, Mr LaPierre urged lawmakers to station armed police officers in all schools by the time students return from the Christmas break in January.
Mr LaPierre did not take questions from reporters.
Earlier, church bells rang out in tree-lined suburban Newtown and up and down the East Coast at 9:30am (2.30pm Irish time) in memory of the victims of the attack on 14 December in which 28 people, including the gunman, were killed.
The gunman, Adam Lanza, used a military-style assault rifle and police said he carried hundreds of bullets in high-capacity magazines, as well as two handguns.
The weapons were legally purchased and registered to his mother, Nancy, his first victim.
The attack, which killed 20 first graders ages 6 and 7, shattered the illusion of safety in this close-knit town of 27,000 people where many residents knew someone affected by the attacks.
Mr LaPierre's comments came at the end of a week when US President Barack Obama commissioned a new White House task force to find a way to quell violence, a challenge in a nation with a strong culture of individual gun ownership.
"We have to have a comprehensive way in which to respond to the mass murder of our children that we saw in Connecticut," Vice President Joe Biden, who heads the task force, said yesterday.
The US Constitution guarantees the right to bear arms and hundreds of millions of weapons are in private hands.
About 11,100 Americans died in gun-related killings in 2011, not including suicides, according to preliminary data from the US Centres for Disease Control and Prevention.
Some US lawmakers called for swift passage of an assault weapons ban.
Some Newtown residents have already launched an effort aimed at tightening rules on gun ownership.