On the eve of the one-month anniversary of the Newtown, Conn., school shooting and days before policy proposals on curbing gun violence are sent to U.S. President Barack Obama, the National Rifle Association says it has enough support in Congress to block a law that would ban assault weapons.

The White House and Democratic lawmakers have vowed to make the ban a reality, and senators plan to introduce a bill that would ban assault weapons and limit the maximum capacity of ammunition magazines.

The ban would target guns like the high-powered Bushmaster AR-15 rifle that was primarily used by the Newtown gunman, Adam Lanza, on Dec. 14. The gun was purchased legally.

Lanza used the rifle to shoot and kill 20 young students and six school staff members before turning the gun on himself. Police later discovered that he had killed his mother prior to the school shooting.

A similar assault weapons ban expired in 2004 and the NRA has successfully prevented the passage of new bans since.

However, some lawmakers say the shooting at Sandy Hook Elementary School transformed the country, and citizens are now ready for tighter gun control.

Following the horrific massacre, the president made gun control a top priority and asked Vice President Joe Biden to lead a task force on curbing gun violence. Biden is expected to present the group’s findings on Tuesday.

The NRA, however, remains confident that it can fend off a new ban.

"When a president takes all the power of his office, if he's willing to expend political capital, you don't want to make predictions. You don't want to bet your house on the outcome. But I would say that the likelihood is that they are not going to be able to get an assault weapons ban through this Congress," NRA president David Keene told CNN's "State of the Union."

Republican Sen. John McCain of Arizona told CBS’s “Face the Nation” that Congress would not pass a ban on assault rifles.

Democratic Sen. Joe Manchin of West Virginia said that all options should be open for discussion when working to prevent another public shooting, but promised gun owners he would continue to fight to protect gun rights under the U.S. Constitution’s Second Amendment.

“I would tell all of my friends in the NRA, I will work extremely hard and I will guarantee you there will not be an encroachment on your Second Amendment rights," the lifelong member of the NRA said on ABC's "This Week."

The powerful lobby group has spent vast amounts of money to lobby lawmakers.

During the 2012 elections the NRA spent at least $24 million -- $16.8 million through its political action committee and nearly $7.5 million through its affiliated Institute for Legislative Action. The group spent another $4.4 million, separately, to lobby Congress through July 1.

Still, Keene insisted that the group represents the interests of its members and not solely gun manufacturers.

"We know what works and what doesn't work. And we're not willing to compromise on people's rights when there is no evidence that doing so is going to accomplish the purpose," Keene said.

Instead, the NRA wants policies enacted that prevent guns from getting into the hands of a mentally ill person, until that person gets better.

“If they are cured, there ought to be a way out of it,” he said.

Current laws ban an individual from buying a gun from a licensed dealer if the person “has been adjudicated as a mental defective or has been committed to any mental institution.”

As well, an individual is prohibited from buying a gun if they are a fugitive, a felon, convicted of substance abuse or domestic violence or living in the U.S. illegally.

However, states are inconsistent in providing information about mentally ill residents to the federal government.

The Brady Campaign to Prevent Gun Violence estimates that around 40 per cent of gun purchases occur with no background checks, many through private sellers over the Internet or at gun shows.

With files from The Associated Press