Ghost guns are handmade or self-assembled firearms that don't have serial numbers. Some can be fabricated in as little as 30 minutes using kits and parts purchased online. Biden will direct the Justice Department to issue a proposed rule to "stop the proliferation" of those weapons, though a senior administration official previewing the step declined to elaborate on how specifically the rule -- due in 30 days -- might work.

Another proposed rule would target stabilizing braces for pistols, which aid in the weapons' accuracy and manage recoil. Under the new rule, the devices -- which the senior administration official contended turn pistols into short barreled rifles -- would be covered by regulations in the National Firearms Act, including requiring registration. Last month's mass shooter in Boulder, Colorado, used a pistol modified with an arm brace, according to a law enforcement source.

The announcements will come as the President is expected to nominate David Chipman as the next director of the Bureau of Alcohol, Tobacco, Firearms and Explosives, a White House official told CNN. Chipman is a former ATF agent who serves as senior policy adviser at Giffords, the organization led by former congresswoman Gabby Giffords, who became a gun control advocate after being shot in 2011.

The ATF has been without a permanent director since 2015.

Biden also plans to announce new investments in intervention programs in violence-prone communities; a directive to the Justice Department to publish model "red flag" laws for states that allow the temporary removal of guns from people deemed at high risk of harming themselves or others; and a comprehensive report on firearms trafficking.

Taken together, the actions amount to the first real steps by Biden's administration to combat gun violence. Inside the White House, efforts to devise executive actions have been led by White House Domestic Policy Council Director Susan Rice and Office of Public Engagement Director Cedric Richmond, administration officials and gun safety advocacy groups told CNN.

That included meeting with some of those groups and fielding ideas for steps that Biden could take on his own. Some advocates had been clamoring for steps earlier in the administration, pointing to Biden's pledge to prioritize gun control during his campaign.

But initial reaction from gun safety advocacy groups Wednesday evening was positive.

"Each of these executive actions will start to address the epidemic of gun violence that has raged throughout the pandemic, and begin to make good on President Biden's promise to be the strongest gun safety president in history," John Feinblatt, president of Everytown for Gun Safety, said in a statement.

"These much-needed executive actions will start saving lives right away, and our grassroots army of nearly 6 million supporters looks forward to standing behind President Biden as he urges the Senate to follow his lead and act," Shannon Watts, founder of Moms Demand Action, said in a statement.

While campaigning, Biden had said he would task his attorney general with instituting better enforcement of existing gun laws as a means of slowing gun violence. He also made a campaign pledge to send $900 million for community programs meant to combat violence, something the administration is sorting out how to fulfill.

Biden acknowledged during a news conference that his main legislative priority was passing an infrastructure package and that he believed careful timing was key to the success of any proposed bills.

And he has acknowledged that his political capital is limited.

"I haven't done any counting yet," he said in March when asked whether he believed he had enough votes to pass significant reforms.

As the nation's posture on guns has evolved, Biden has been front-and-center at most every stop along the way for more than three decades, from the triumph of a 10-year ban on assault weapons in 1994 to the disappointment of a failed push for universal background checks in the wake of the Sandy Hook massacre.

Recent shootings in Georgia and Colorado had raised the question inside the West Wing over how much political capital Biden should expend on the matter, which has so often ended in frustration.

This story has been updated with details about Biden's executive actions and reaction to them.