President Barack Obama has moved to tighten gun laws in the US following a series of mass shootings, claiming his plan would save lives.
But the proposals were sure to lead to opposition in Congress and the powerful gun industry lobby.
Mr Obama wants to require all gun sellers to register as dealers – even those who sell at gun shows and online – and to run background checks on all prospective purchasers.
The president has been looking for ways to work around a Republican-led Congress that has blocked his previous efforts to tighten gun laws in the wake of mass shootings.
Mr Obama has accused Republicans – and some Democrats – of being beholden to the gun industry lobby and opposing some measures he says a majority of Americans support, including expanded background checks on gun sales.
But the issue of gun control bitterly divides Americans, with many viewing any attempt to regulate firearms as a possible infringement on their constitutional rights to own guns.
“This is not going to solve every violent crime in this country,” Mr Obama said. But he added: “It will potentially save lives and spare families the pain of these extraordinary losses.”
The president’s plan to broaden background checks forms the centrepiece of a broader package of measures he wants to take on his own on gun control in his final year in office.
Although Mr Obama cannot unilaterally change gun laws, the president is hoping that beefing up enforcement of existing laws can prevent at least some gun deaths in a country rife with them.
Under current law, only federally licensed gun dealers must conduct background checks on buyers.
But many who sell guns at flea markets, on websites or other informal settings do not register as dealers. Gun control advocates say that loophole is exploited to skirt the background check requirement.
The executive actions on gun control fall far short of what he and like-minded politicians attempted to accomplish with legislation in 2013, after a massacre at a Connecticut school that shook the nation’s conscience.
Even so, the more modest measures were sure to spark a confrontation with Republicans and gun rights groups that oppose new impediments to buying guns.
“We’re very comfortable that the president can legally take these actions now,” said Attorney General Loretta Lynch.
Mr Obama’s announcement was hailed by Democratic politicians and gun control groups like the Brady Campaign to Prevent Gun Violence, which claimed he was making history with “bold and meaningful action” that would make all Americans safer.
Democratic presidential front-runner Hillary Clinton, at a rally in Iowa, said she was “so proud” of Mr Obama but warned that the next president could easily undo his changes.
“I won’t wipe it away,” she said.
Republicans were quick to attack Mr Obama, with Senator Bob Corker denouncing his steps as “divisive and detrimental to real solutions”.
He said: “I will work with my colleagues to respond appropriately to ensure the Constitution is respected.”
Far from mandating background checks for all gun sales, the new guidance still exempt collectors and gun hobbyists, and the exact definition of who must register as a dealer and conduct background checks remains vague.
The administration did not issue a number for how many guns someone must sell to be considered a dealer, instead saying it planned to remind people that courts have deemed people to be dealers in some cases even if they only sell a handful of guns.