The National Rifle Association (NRA) promised "to offer meaningful contributions to help make sure this never happens again".
US President Barack Obama is "actively supportive" of reinstating an assault weapons ban, the White House said, as the United States wrestled with the treacherous issue of gun control in the aftermath of the Connecticut school massacre.
In Newtown, where the shooting occurred, funerals were held for two more of the little victims, six-year-old Jack Pinto and Allison Wyatt (also six), the latest in a long, almost unbearable procession of grief.
Tributes were paid to little Allison, one of the first victims of the rampaging gunman.
"Our world is a lot darker now that she's gone. We love and miss her so much," her parents said in a statement.
Twenty six people were gunned down at Sandy Hook Elementary School in one of the worst mass shootings in US history. The gunman, who committed suicide, also killed his mother in her home.
The massacre has rattled the usual national dialogue on guns in America, where public opinion had shifted against tougher arms control in recent years and the gun lobby is a powerful political force.
Congressional gun rights supporters showed an increased willingness yesterday to consider new legislation -- provided it also addressed mental health issues and the impact of violent video games.
Republicans in the House of Representatives discussed the gun issue at their regular closed-door meeting and some were willing to consider gun control.
White House spokesman Jay Carney said Mr Obama was "actively supportive" of reinstating an assault weapons ban and would also support laws to close the gun show "loophole", which allows people to buy guns without background checks.
Mr Obama has long supported reintroducing the assault weapons ban, which expired in 2004, but was quiet on the issue during his first term.
The most powerful supporter of gun owners, the National Rifle Association, broke its silence yesterday, four days after the school shooting.
After a self-imposed media blackout that left many wondering how it would respond to the killings, it said in a statement that its members were "shocked, saddened and heartbroken by the news of the horrific and senseless murders".
The group -- typically outspoken about its positions even after shooting deaths -- said it wanted to give families time to mourn before making its first public statements.
"The NRA is prepared to offer meaningful contributions to help make sure this never happens again," the group said.