Speaking close to the site of the Connecticut school massacre, US Vice President Joe Biden said public opinion had turned against the gun rights lobby.
Mr Biden told a conference on gun violence: "I say it's unacceptable not to take this on. ... I believe the price to be paid politically is for those who refuse to act,"
He was speaking during a visit in the Connecticut area where a gunman killed 20 school children and six adults in the nearby town of Newtown on 14 December 2012.
The courage displayed by the affected Newtown families should rub off on elected officials, Mr Biden said.
"It's not too much to ask the political establishment ... to show some courage also," he said.
Mr Biden has taken the lead in promoting US President Barack Obama's gun-control proposals.
The proposals include universal background checks, a ban on assault weapons and high-capacity magazines, a federal gun-trafficking statute, more police, and more research on gun violence.
He told the Gun Violence Forum hosted by the state's two Democratic US Senators, Richard Blumenthal and Chris Murphy, that people in Connecticut need not surrender to hopelessness in the wake of the shooting because there is "much we can do".
After decades in which the pro-gun lobby, as exemplified by the National Rifle Association, has dominated the debate, gun-control advocates say public opinion has changed.
About three-quarters of Americans surveyed support proposals to ban the sale of automatic weapons, ban high-capacity ammunition magazines and expand background checks on all gun buyers, according to an online Reuters/Ipsos poll released on 17 January.
Mr Biden acknowledged that no reforms will "save every life", but said he believed enacting Mr Obama's proposals would mean "fewer children will die".
The ideas were largely echoed by a proposal put forward yesterday by Connecticut Governor Dannel Malloy.
Connecticut already has an assault weapons ban, and Mr Malloy is urging politicians to expand it to include any semi-automatic weapon with at least one military-style characteristic, such as a pistol grip, bayonet lug or flash suppressor.
"Two months ago, our state became the centre of a national debate after a tragedy we never imagined could happen here," said Mr Malloy, who spoke shortly before Mr Biden.
"We have changed. And I believe it is now time for our laws to do the same."
Whatever laws Connecticut enacts, "the need for strong federal legislation has never been clearer," Mr Malloy said.
Connecticut, a largely Democratic state, already has some of the toughest gun laws in the country.