Emotional Obama seeks to tighten US gun control
US president Barack Obama was in tears as he unveiled plans to tighten gun control in America, using his presidential powers in the absence of legal changes he had implored Congress to pass.
Mr Obama accused the gun lobby of having taken Congress hostage, but declared: "They cannot hold America hostage."
He insisted it is possible to uphold the US Second Amendment while doing something to tackle the frequency of mass shootings in America that he said had become "the new normal".
The much-debated Second Amendment of the Constitution guarantees the right of US citizens to own firearms.
Mr Obama insisted: "This is not a plot to take away everybody's guns.
"You pass a background check, you purchase a firearm. The problem is, some gun sellers have been operating under a different set of rules."
Mr Obama's actions ensure that gun rights - one of the most bitterly divisive issues in America - will be at the forefront of the 2016 presidential campaign, which begins in earnest next month with the first primary contests.
Accusing Mr Obama of overreaching his responsibilities, many of the Republican presidential candidates have vowed to rip up the new gun restrictions upon taking office.
Democratic front-runner Hillary Clinton said she was proud of Mr Obama's efforts and promised she would safeguard them.
The US president wiped tears away as he recalled the 20 young children killed in 2012 at Sandy Hook Elementary School in Newtown, Connecticut.
He paid tribute to the parents - some of whom were present for the announcement - who he said had never imagined their child's life would be cut short by a bullet.
"Every time I think about those kids, it gets me mad," Mr Obama said.
At the centrepiece of Mr Obama's plan is a more sweeping definition of gun dealers that the administration hopes will expand the number of sales subject to background checks.
Under current law, only federally-licensed gun dealers must conduct background checks on buyers. But at gun shows, websites and flea markets, sellers often skirt that requirement by declining to register as licensed dealers.
Aiming to close that loophole, the US Justice Department's Bureau of Alcohol, Tobacco, Firearms and Explosives is issuing updated guidance that says the government should deem anyone "in the business" of selling guns to be a dealer, regardless of where he or she sells the guns.
The government will also consider other factors, including how many guns a person sells, how frequently, and whether those weapons are sold for a profit.
The White House also put sellers on notice that the administration planned to strengthen enforcement - including deploying 230 new examiners the FBI will hire to process background checks.
Public opinion polls show Americans overwhelmingly support expanding background checks for gun purchases, but are more divided on the broader question of stricter gun laws.
About a third of Americans live in a household where at least one person owns a gun. Particularly in rural areas where firearms are a way of life, many citizens do not believe gun laws should be tightened.
The reverse is true in urban areas, where majorities want more thorough firearm regulations.
Had the rules been in place in the past, the steps would not likely have prevented any of the recent mass shootings that have garnered national attention. The Obama administration acknowledged it could not quantify how many gun sales would be newly subjected to background checks, nor how many currently unregistered gun sellers would have to obtain a licence.
Responding to that critique, Mr Obama said every time the issue is debated, gun rights groups argue the steps would not necessarily have stopped the last massacre, "so why bother trying?"
"I reject that thinking," he said, arguing it would be worth it if the measures prevented even a single gun death.
"We maybe can't save everybody, but we could save some."
To lend a personal face to the issue, the White House assembled a cross-section of Americans whose lives were altered by recent gun tragedies, including former representative Gabrielle Giffords and relatives of victims from Charleston, South Carolina and Virginia Tech.
Mark Barden, whose son was shot dead at Sandy Hook, introduced the president with a declaration that "we are better than this".
After Newtown, Mr Obama sought far-reaching, bipartisan legislation that went beyond background checks.
When that effort collapsed in the Senate, the White House said it was thoroughly researching the president's powers to identify every legal step he could take on his own.
But a more recent spate of gun-related atrocities, including in San Bernardino, California, have spurred the administration to give the issue another look, as Mr Obama seeks to make good on a policy issue he has pushed time and again but has not advanced - until now.