Obama also may order the Justice Department to crack down on people who lie on gun-sale background checks; only a tiny number are now prosecuted. Such a step has support from the NRA, which has consistently argued that existing laws must be enforced before new ones are considered.
And Obama may give schools flexibility to use grant money to improve safety. But he is not expected to call for armed guards in schools, a position promoted by the NRA.
The gun lobby 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.
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.
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.
During his announcement Wednesday, Obama will be joined children from across the U.S. who wrote letters to him about gun violence and school safety.
One of those children, a Maryland 8-year-old named Grant, wrote: "It's a free country but I recommend there needs (to) be a limit with guns. Please don't let people own machine guns or other powerful guns like that."
It's unclear how much political capital Obama will exert in pressing for congressional action.