The United States' largest gun rights lobby says it wants to address gun violence by placing armed police officers in every school in America, while two Democratic senators called the group's response to the Newtown tragedy shamefully inadequate.

The executive vice president of the powerful National Rifle Association, or NRA, said tragedies like the massacre at Sandy Hook Elementary School in Newtown, Connecticut, last week could be prevented by armed security, adding that “the only thing that stops a bad guy with a gun is a good guy with a gun.”

The NRA's Wayne LaPierre spoke Friday in Washington, one week after 26 people were gunned down at the school. He also blamed movies and video games for exposing U.S. children to a violent culture.

The NRA news conference was disrupted twice by protesters who blamed the group for gun violence. One protester held up a banner to the cameras that said, “NRA killing our kids.”

Two Democratic senators responded to the NRA statement by labeling it a delay tactic aimed at stalling a real conversation about gun control.

Senator Dianne Feinstein of California has said she will introduce legislation on reauthorizing an assault weapons ban.

“We cannot ignore the common denominator in all of these deadly massacres – access, easy access to killing machines.”

Senator Richard Blumenthal, who represents Connecticut, called the NRA statement “shamefully inadequate.”

“The refrain I have heard again and again and again from the people of Newtown and Connecticut and all around the country is, 'you need to do something about the guns.'”

Earlier, President Barack Obama and other Americans paused to remember those killed a week ago. Church bells rang in Newtown and other U.S. towns and cities as mourners stood in silence.

The December 14 attack at Sandy Hook Elementary was the second-worst school shooting in U.S. history.

After the attack, President Obama said action is needed to prevent such a tragedy in the future. He has called on Congress to reinstate the assault weapons ban that lapsed in 2004. The gunman in the Newtown attack used a military-style weapon.

The worst U.S. school shooting occurred in 2007, when a gunman opened fire at a Virginia university, killing 32 people before taking his own life.