National Rifle Association President David Keene in Washington, D.C., in December. (PAUL J. RICHARDS/AFP/Getty Images)

Opposing forces in the debate over the nation’s gun laws staked out starkly different positions Sunday, with the head of the largest gun rights group declaring confidence that a ban on assault weapons would not win passage from lawmakers, while advocates of tightening restrictions on guns said such measures can be approved.

“I would say that the likelihood is that they are not going to be able to get an assault weapons ban through this Congress,” National Rifle Association President David Keene said on CNN’s “State of the Union.”

Keene’s comments came two days before a self-imposed deadline for an Obama administration task force led by Vice President Biden to offer concrete policy recommendations on curbing gun violence.

Obama has already said he supports renewing an expired ban on assault rifles and high-capacity magazines, while gun control advocates on Capitol Hill have promised to lead a charge to pass such a measure. Sen. Dianne Feinstein (D-Calif.) will soon introduce such a ban in the Senate.

But the staunchest gun rights advocates, led by the NRA, have shown no willingness to endorse tightened restrictions on guns. After Biden’s working group met with the NRA last week, the gun rights group said it was “disappointed” with how little the meeting “had to do with keeping our children safe and how much it had to do with an agenda to attack the Second Amendment.”

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The direction of the national gun debate will grow clearer after Biden’s group delivers its recommendations to the president. The vice president said last week that he was beginning to see an emerging consensus from gun control advocates and law enforcement officials he had met with around “universal background checks” for all gun buyers and a ban on high-capacity ammunition magazines.

Others have cautioned that any new restrictions on guns must be part of a comprehensive attempt to curb mass violence, including a closer look at security, the entertainment industry and mental health issues.

“An assault weapons stand-alone ban on just guns alone, in the political reality we have, will not go anywhere. It has to be comprehensive,” Sen. Joe Manchin (D-W.Va.) said on “State of the Union.” Manchin, a conservative, is the recipient of an “A” rating from the NRA.

Speaking from Newtown, Conn., where 20 children and six adults were fatally shot in an elementary school on Dec. 14, Sen. Chris Murphy (D-Conn.) said on the same program that he disagreed with Keene about the prospects of new gun control legislation winning passage in Congress.

“Newtown fundamentally changed things. And the NRA just fundamentally doesn’t get this,” Murphy said.

Groups on both sides of the debate are gearing up for what could be a tense legislative battle. Neera Tanden, president of the liberal think tank Center For American Progress, vowed a grass-roots effort among gun control advocates for new restrictions.

“I expect the president to play a strong leadership role, but progressive organizations will be working to — working with the states to show that we have the voice and really have the American people,” said Tanden on “Fox News Sunday.”

For their part, gun rights advocates continued to argue in favor of arming qualified citizens in an attempt to curb mass violence.

“We have got to face the reality that we have got to empower average people, including teachers and other people in schools, to be able to defend themselves,” said Gun Owners of America Executive Director Larry Pratt.

Former secretary of state Colin Powell offered optimism that lawmakers can reach an accord on at least incremental measures to curb gun violence.

“I think we’re at a very important point in our national dialogue on this,” Powell said on NBC News’s “Meet the Press.” “The NRA feels very, very strongly, gun owners feel very, very strongly, and at the same time the American people are concerned about the kinds of things that are happening in our society. Surely if we can’t get the whole ball of wax, I hope that there will be a way to find something in this continuum of things we can do that we’re able to do to demonstrate to the American people that this problem’s being taken seriously.”