US President Barack Obama is to issue a set of executive orders to tighten gun control in a bid to reduce firearm-related deaths in the country.
The package, which will officially be announced on Tuesday despite fierce opposition in the Congress, will require all gun sellers to register as dealers and run background checks on all prospective buyers.
Obama, who is on the final year of his presidency, said the move was "well within" his legal authority and the executive branch.
"This is not going to solve every violent crime in this country, it's not going to prevent every mass shooting, it's not going to keep every gun out of the hands of a criminal but it will potentially save lives in this country," he said on Monday after a meeting with US Attorney General Loretta Lynch.
Yet, opponents have threatened to challenge Obama's actions, saying the president is exceeding his legal authority.
The top Republican in Congress, Speaker of the House Paul Ryan, said Obama's plans reached "a dangerous level of executive overreach, and the country will not stand for it."
Many of the Republican presidential candidates have pledged to rip up new Obama gun restrictions upon taking office, and some politicians are contemplating withholding Justice Department funds if it tries to implement them.
"I will work with my colleagues to respond appropriately to ensure the Constitution is respected," said Republican Senator Bob Corker.
But Democratic presidential frontrunner Hillary Clinton endorsed the Obama initiative, describing it as "bold and meaningful action".
Under the plan announced by the White House, America's Bureau of Alcohol, Tobacco, Firearms and Explosives will require all gun sellers to obtain a license whether they are selling from store, gun show, flea market or over the internet.
"If you're in the business of selling firearms, you must get a license and conduct background checks," the White House said in a statement on Monday.
The FBI will also boost its workforce for processing background checks by 50 percent, hiring more than 230 new examiners and staff.
Obama will also ask Congress to invest $500 million to increase access to mental healthcare, while the defense and homeland security departments will be required to do more research on smart gun technology.
READ MORE: Obama pledges to act unilaterally on US gun control
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.
Although Obama can't unilaterally change gun laws, he is hoping that beefing up enforcement of existing laws can prevent at least some gun deaths in a country rife with them.
More than 100,000 have been killed as a result of gun violence in the last 10 years, according to US officials.