President Barack Obama on Wednesday set up a task force to frame "concrete proposals" on ending an "epidemic" of firearms violence by next month, and denied he had been on "vacation" on gun control.

With trauma still raw after the Connecticut school massacre last week, Obama put Vice President Joe Biden in charge of an inter-agency effort on gun control and mental health, saying America had a "deep obligation" to act.

Obama, who failed to put political muscle behind greater gun control after previous mass slaughters, dismissed the notion that the task force would simply be a familiar, toothless Washington policy commission with little impact.

And he said killings of 20 children aged six and seven and six teachers and caregivers in the elementary school in Newtown were so horrific they should give lawmakers a potent incentive for action, even when initial shock fades.

"I would hope that our memories aren't so short that what we saw in Newtown isn't lingering with us, that we don't remain passionate about it only a month later," Obama said at the White House.

"This is a team that has a very specific task to pull together real reforms right now, adding he was seeking ways to "reduce the epidemic of gun violence that plagues this country every single day."

"I will be putting forward very specific proposals. I will be talking about them in my State of the Union, and we will be working with interested members of Congress to try to get something done."

Obama urged the often slow-moving Congress to hold timely votes on banning military-style assault weapons like the one used by gunman Adam Lanza in Newtown and also on outlawing the sale of high-capacity ammunition clips.

He also called for new laws to ensure background checks for all gun purchases and signaled an effort to expand mental health care, in an effort to deter psychologically troubled people from turning to mass violence.

"We're going to need to make access to mental health at least as easy as access to a gun. We're going to need to look more closely at a culture that, all too often, glorifies guns and violence," he said.

Biden has a history of framing crime legislation from his years in the Senate, has an affinity with law enforcement services and also enjoys the kind of cordial links with many top Republicans in Congress that Obama lacks.

Obama, who comforted relatives of Newtown victims on Sunday, bristled when asked by a reporter whether he had been absent on gun control issues, following mass killings in Colorado, Arizona and Texas on his watch.

"I've been president of the United States, dealing with the worst economic crisis since the Great Depression, an auto industry on the verge of collapse, two wars. I don't think I've been on vacation."

Obama, who many conservatives believe wants to take away their guns, also said he supported the Second Amendment to the Constitution, which enshrines the right to bear arms in the United States.

"There is a big chunk of space between what, you know, the Second Amendment means and having no rules at all," he said.

Obama also called on the National Rifle Association, the most powerful gun lobby group which piles pressure on lawmakers over gun rights, to consider its priorities, before senior figures hold a news conference on Friday.

"The NRA is an organization that has members who are mothers and fathers, and I would expect that they've been impacted by this as well, and hopefully they'll do some self-reflection," he said.

The aftermath of the horrific shootings in Connecticut has prompted some pro-gun figures on Capitol Hill to admit that more needs to be done to regulate the sale and use of firearms.

But most evidence of shifting positions has been among Democrats, and there are signs that Republicans, especially those from rural, southern and conservative states may balk at new legislative action.

Democratic Representative Catherine McCarthy, whose husband was gunned down on a New York train in December 1993, however said the uproar after this massacre was different.

"We are fed up with the lack of courage here in Washington to take a stand, to do something," she said.

"We can protect the Second Amendment rights, but we can also protect our communities."

In another development Wednesday, Democratic Senator Jay Rockefeller announced a bill that would require a National Academy of Sciences assessment of links between violent games and violence.

Lanza was reportedly a fan of violent videogames.