WASHINGTON — Facing powerful opposition to sweeping gun regulations, President Barack Obama is weighing 19 steps he could take through executive action alone, congressional officials said. But the scope of such measures is limited.

The steps could include ordering stricter action against people who lie on gun sale background checks, seeking to ensure more complete records in the federal background check database, striking limits on federal research into gun use, ordering tougher penalties against gun trafficking, and giving schools flexibility to use grant money to improve safety.

Obama will unveil his proposals Wednesday, barely over a month since the massacre of 20 children and six adults at Sandy Hook Elementary School in Newtown, Conn., thrust the gun issue into the national spotlight after years of inaction by Obama and lawmakers.

The White House said Obama and Vice President Joe Biden will be joined at Wednesday's announcement by children who wrote the president letters after the Newtown shooting. Supportive lawmakers and advocacy groups are also expected to attend.

Obama is vowing not to back off his support for sweeping gun legislation that would require congressional backing — including banning assault weapons, limiting the capacity of ammunition magazines and instituting universal background checks — despite opposition from the influential gun lobby.

"Will all of them get through this Congress? I don't know," Obama said at a news conference Monday.

"My starting point is not to worry about the politics," he said. "My starting point is to focus on what makes sense, what works."

The president said he would unveil a comprehensive roadmap for curbing gun violence within days. His plan will be based on recommendations from Biden's gun task force and is expected to include both legislative proposals and steps Obama can implement by himself, using his presidential powers.

White House officials believe moving swiftly on gun proposals at a national level, before the shock over the Newtown shooting fades, gives Obama the best chance to get his proposals through Congress.

Officials said Obama and Biden met Monday afternoon to discuss the vice president's recommendations. Ahead of that meeting, Biden huddled with a dozen House Democrats who have formed their own gun violence task force and whose political muscle will be needed to push legislation through Congress.

Biden told those lawmakers that he and his staff had identified 19 steps Obama could take without help from Congress, according to Jenny Werwa, communications director to Rep. Jackie Speier, D-Calif., one of those present. Biden didn't indicate which of those Obama would adopt.

Rep. Bobby Scott, D-Va., another lawmaker at the meeting, said one example is working to ensure better state reporting of mental health and other records that go into the federal background check database. But Scott said there are clear limits to what Obama can do without Congress' say-so.

"It wasn't anything remarkable, it was just administering present law better," Scott said. "You can't change the law through executive order."

Among other steps, advocacy groups have been pushing Obama to order the Justice Department to crack down on those 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.

Obama 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, advocates said.

The president's proposals are also expected to include steps for improving school safety and mental health care, as well as recommendations for addressing violence in entertainment and video games.

"You'll have a combination of gun safety, mental health and general prevention," Scott said.

Another Democratic lawmaker who met with Biden on Monday said the vice president was likely to have given Obama proposals for allowing schools flexibility in spending federal grant money so they could take steps toward safety, including hiring school resource officers, instituting mental health intervention or making repairs like putting locks on doors. Grants could also go to communities to institute programs to get guns away from people who shouldn't have them, said the lawmaker, adding these were steps the president could take without Congress.

The lawmaker spoke on condition of anonymity because the proposals hadn't been announced publicly.

But the most sweeping and contentious elements — including an assault weapons ban — will require approval from Congress. The NRA has vowed to fight any measure that would limit access to guns and ammunition, a hardline position that could sway some Republicans and conservative Democrats.

The assault weapons ban, which Obama has long supported, is expected to face the toughest road on Capitol Hill. Congress passed a 10-year ban on the high-grade, military-style weapons in 1994, but supporters didn't have the votes to renew it once it expired.

Obama will also need congressional help to limit high-capacity ammunition magazines, like the ones used by the Newtown shooter, and to require background checks for anyone seeking to purchase a gun. The Brady Campaign to Prevent Gun Violence said some 40 percent of gun sales happen with no background checks, such as at gun shows and by private sellers over the Internet or through classified ads.

Parents of the slain Connecticut children added their voices to the national dialogue Monday. Members of the newly formed group Sandy Hook Promise called for an open-minded discussion about a range of issues, including guns. And lawmakers in New York state pressed ahead with what would be the nation's first gun control measure approved since the school shootings.

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AP White House Correspondent Julie Pace contributed to this report.