President Barack Obama put ending an "epidemic" of gun violence at the top of his second term agenda Wednesday, denying he was "on vacation" on the issue before last week's school massacre.

Obama called for "concrete" proposals within a month from a new task force that will be led by Vice President Joe Biden that will examine new gun control laws, better mental health access and the impact of violent culture.

"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 said.

The president said the killings of 20 children aged six and seven and six adults in an elementary school last week should give lawmakers a potent incentive for action, even when initial shock fades.

"The fact that this problem is complex can no longer be an excuse for doing nothing. The fact that we can't prevent every act of violence doesn't mean we can't steadily reduce the violence, and prevent the very worst violence."

Obama said he welcomed public support for measures like the banning of assault weapons, like the one used by gunman Adam Lanza in Connecticut last Friday, and also on outlawing the sale of high-capacity ammunition clips.

He said a majority of Americans also supported 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.

Obama spoke with Americans still traumatized by Lanza's horrific gun rampage, and as more of the victims were laid to rest in the grief stricken picture postcard town in Connecticut.

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.

He will begin his work on Thursday, meeting senior law enforcement leaders from across the United States and key cabinet members at the White House.

Obama's timeline means he will make new legislation to stem gun violence one of the first major issues of his second term, after he is sworn in on January 20.

The president, 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.