The "meaningful action" that President Obama promised after a mass shooting in Connecticut last week began to take shape Tuesday, as the White House said it would support a fresh push to renew an assault weapons ban and other new gun laws.

In addition to the proposed prohibition on assault weapons, White House press secretary Jay Carney said the president would back legislation that closed so-called gun show loopholes and cracked down on high-capacity ammunition clips. Progressives have long targeted gun shows, saying weapon sales at such events did not require the same background and identification checks as purchases made at stores.

Those were the first concrete measures Obama has publicly supported since the killing of 20 school children and six adults at Sandy Hook Elementary School in Newtown last week.

Sen. Dianne Feinstein is planning to introduce an assault weapons ban on the first day of the new Congress, potentially renewing a law that expired in 2004 -- a task that cleared its first hurdle Tuesday with the endorsement of the White House.

The prospects for changes to the nation's firearms laws appeared stronger than at any time since the assault weapons ban passed in 1994. Even some congressional Republicans from conservative bastions in the Deep South suggested on Tuesday they were open to a re-examination of the nation's gun culture.

"Put guns on the table, also put video games on the table, put mental health on the table," Rep. Jack Kingston, R-Ga., said after a meeting in which GOP lawmakers discussed gun control. And Sen. Lindsey Graham, R-S.C., said he was open to exploring limitations on ammunition clips.

The shooter at Sandy Hook Elementary, Adam Lanza, reportedly played violent video games and suffered from a learning disability.

The gun debate took various forms around the country in the wake of the killings. On Tuesday, Gov. Rick Snyder, R-Mich., vetoed gun legislation that would have allowed concealed weapons in the state's churches, schools and day cares. Virginia Gov. Bob McDonnell on Tuesday said he'd consider whether teachers and principals should be armed. And Maryland Gov. Martin O'Malley predicted stronger gun registration laws were ahead in that state.

The Obama administration has a variety of executive options at its disposal that don't require congressional approval. The president could beef up background checks, require more extensive records of gun sales or limit military-style weapons, administration officials said. Obama has appointed Vice President Biden to spearhead proposals from his Cabinet for how to prevent similar massacres in the future. The president said he would outline his agenda in "coming weeks."

Obama phoned Sen. Joe Manchin, D-W.Va., a National Rifle Association-endorsed candidate, who this week suggested he might back a ban on assault weapons.

"I believe that we must have a dialogue and bring parties from all sides to the table," Manchin said after his conversation with Obama. "I know my friends at the NRA and those who support our Second Amendment rights will participate because I know that their hearts are aching for the families in Newtown, just like all Americans."

The NRA has not yet indicated whether it plans to fight the push for new gun restrictions, as it has during past national debates on the topic.

At a press conference on Tuesday, the organization said it was prepared to "offer meaningful contributions to help make sure this never happens again."