Obama may order the Justice Department to crack down on people who lie on background checks; only a tiny number are now prosecuted. Such a step has support from the National Rifle Association, which has consistently argued that existing laws must be enforced before new ones are considered.
He also could take steps ordering federal agencies to make more data on gun crimes available and conduct more research on the issue, something Republican congressional majorities have limited through language in budget bills. And he may order tougher penalties against gun trafficking and give schools flexibility to use grant money to improve safety.
Gun control proponent Rep. Bobby Scott, D-Va., who met with Biden on Monday, said the president is also likely to take executive action to ensure better state reporting of mental health and other records that go into the federal background check database. But he, too, acknowledged there were clear limits to what Obama can do without Congress' say-so.
"You can't change the law through executive order," Scott said.
The NRA released an online video Tuesday that called Obama an "elitist hypocrite" for having armed Secret Service agents protect his daughters at school while not committing to installing armed guards in all schools.
White House officials signaled that Obama would seek to rally public support for the measures he puts forward, perhaps holding events around the country or relying on Organizing for America, his still-operational presidential campaign.
"The president's success in using this strategy, I think, is pretty notable," Carney said of Obama's efforts to engage the public in previous legislative fights. "He'll absolutely continue to engage with the American people on the policy proposals he's putting forward."
Still, it's unclear how much political capital Obama will exert in pressing for congressional action.
The White House and Capitol Hill will soon be consumed by three looming fiscal deadlines, each of which is expected to be contentious. And the president has also pledged to tackle comprehensive immigration reform early this year, another effort that will require Republicans' support and one in which Obama may be more likely to get their backing.
Kentucky Sen. Mitch McConnell, the chamber's top Republican, has warned the White House that it will be at least three months before the Senate considers gun legislation. And Senate Majority Leader Harry Reid has said it is immigration, not gun control, that is at the top of his priority list after the fiscal fights.
House Republican leaders are expected to wait for any action by the Senate before deciding how — or whether — to proceed with any gun measure. Publicly, House GOP leaders are being careful not to rule anything out ahead of Obama's announcement.
"I can't respond to any particulars because I haven't even looked at the Biden recommendations, but I can tell you we're all very concerned about the deaths that occurred and the innocent lives lost, and if we bear that in mind, the kinds of things we can do to help make that not happen again," House Majority Leader Eric Cantor, R-Va., said Tuesday.
Privately, House Republicans voice skepticism that the debate will even get to the point of Senate action that would require a response by the House.
Associated Press writers Josh Lederman in Washington and Michael Virtanen in Albany, N.Y., contributed to this report.