President Joe Biden will unveil a series of executive actions aimed at addressing gun violence on Thursday, according to a person familiar with the plans, delivering his first major action on gun control since taking office.

He’s also expected to nominate David Chipman, a former federal agent and adviser at the gun control group Giffords, to be director of the Bureau of Alcohol, Tobacco, Firearms and Explosives.

Two people familiar with the matter told The Associated Press that Chipman’s nomination is expected to be announced Thursday. The people could not discuss the matter publicly ahead of an official announcement and spoke to The AP on condition of anonymity. If confirmed, Chipman would be the agency’s first permanent director since 2015.

Biden has faced increasing pressure to act on gun control after a spate of mass shootings across the U.S. in recent weeks, but the White House has repeatedly emphasized the need for legislative action on guns. While the House passed a background-check bill last month, gun control measures face slim prospects in an evenly-divided Senate, where Republicans remain near-unified against most proposals.

Biden is expected to announce tighter regulations requiring buyers of so-called “ghost guns” to undergo background checks. The homemade firearms — often assembled from parts and milled with a metal-cutting machine — often lack serial numbers used to trace them. It’s legal to build a gun in a home or a workshop and there is no federal requirement for a background check.

The president’s plans were previewed by a person familiar with the expected actions who was not authorized to publicly discuss them. Biden will be joined by Attorney General Merrick Garland at the event.

The ATF is currently run by Acting Director Regina Lombardo. Gun-control advocates have emphasized the significance of the ATF director in enforcing the nation’s gun laws, and Chipman is certain to win praise from them. During his time as a senior policy adviser with Giffords, he spent considerable effort pushing for greater regulation and enforcement on “ghost guns,” reforms of the background check system and measures to reduce the trafficking of illegal firearms.

Prior to that, Chipman spent 25 years as an agent at the ATF, where he worked on stopping a trafficking ring that sent illegal firearms from Virginia to New York, and served on the ATF’s SWAT team. Chipman is a gun owner himself.

Chipman and a White House spokesman both declined to comment.

During his campaign, Biden promised to prioritize new gun control measures as president, including enacting universal background check legislation, banning online sales of firearms and the manufacture and sale of assault weapons and high-capacity magazines. But gun-control advocates have said that while they were heartened by signs from the White House that they took the issue seriously, they’ve been disappointed by the lack of early action.

Biden himself expressed uncertainty late last month when asked if he had the political capital to pass new gun control proposals, telling reporters, “I haven’t done any counting yet.”

White House press secretary Jen Psaki said last month, however, that executive actions on guns were coming as well, calling them “one of the levers that we can use” to address gun violence.

For years, federal officials have been sounding the alarm about an increasing black market for homemade, military-style semi-automatic rifles and handguns. Ghost guns have increasingly turned up at crime scenes and in recent years have been turning up more and more when federal agents are purchasing guns in undercover operations from gang members and other criminals.

It is hard to say how many are circulating on the streets, in part because in many cases police departments don’t even contact the federal government about the guns because they can’t be traced.

Some states, like California, have enacted laws in recent years to require serial numbers be stamped on ghost guns.

The critical component in building an untraceable gun is what is known as the lower receiver, a part typically made of metal or polymer. An unfinished receiver — sometimes referred to as an “80-percent receiver” — can be legally bought online with no serial numbers or other markings on it, no license required.

A gunman who killed his wife and four others in Northern California in 2017 who had been prohibited from owning firearms built his own to skirt the court order before his rampage. And in 2019, a teenager used a homemade handgun to fatally shoot two classmates and wound three others at a school in suburban Los Angeles.

Plans for Biden’s announcement Thursday were first reported by Politico.