Donald Trump has signed an order recommending a ban on devices that turn rifles into machine guns.
Amid public anger following last week's mass shooting at a school in Florida, the President said: "We must do more to protect our children."
The planned clampdown would target rapid-fire bump stocks similar to those used in the Las Vegas massacre last year.
Additionally, the White House has announced age restrictions for buying AR-15 rifles are "on the table". The current age limit for buying an AR-15 is 18, but it is 21 to buy a handgun.
Mr Trump's announcement was made during a ceremony recognising the bravery of America's public safety officers - including some of those who have responded to mass shootings.
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Bump stocks turn semi-automatic weapons into an automatics and were used by gunman Stephen Paddock, who killed 58 people and injured hundreds more when he opened fire on a Las Vegas concert in October.
The device replaces a rifle's standard stock, allowing the weapon to move back and forth more rapidly.
Mr Trump said: "School safety is a top priority for my administration.
"This includes implementing common-sense security measures and addressing mental health issues, including better coordination between federal and state law enforcement to take swift action when there are warning signs.
"In addition, after the deadly shooting in Las Vegas, I directed (the) attorney general to clarify whether certain bump stock devices like the one used in Las Vegas, are illegal under current law.
"Just a few moments ago, I signed a memorandum directing the attorney general to propose regulations to ban all devices that turn legal weapons into machine guns."
Mr Trump added that he wanted to moved past "cliches and tired debates" to bring in security measures that will "actually work" - and said new regulations would be finalised "very soon".
A Justice Department spokeswoman said it had "acted quickly to move through the rule-making process".
Congress has yet to pass any legislation on gun modifications.
According to the New York Times, the National Rifle Association (NRA) has previously backed further regulations on bump stocks.
Mr Trump's memorandum adds: "Although I desire swift and decisive action, I remain committed to the rule of law and to the procedures the law prescribes.
"Doing this the right way will ensure that the resulting regulation is workable and effective and leaves no loopholes for criminals to exploit."
The White House has said Mr Trump will meet with students, teachers, state and local officials to discuss ways of improving school safety and addressing gun violence.
Nikolas Cruz has been charged with 17 counts of murder over the shooting at his former high school in Florida.
Cruz made his second appearance in court earlier this week , and he is understood to be ready to plead guilty as long as the death penalty is not considered.
The mass shooting is one in a long history of massacres in US schools , but has moved people to push again for tighter gun control.
According to a Quinnipac University poll, voters support stricter gun laws by 66% to 31%.
Students from the Florida school affected and those around them have been marching to call for greater regulation in the last few days.
But, just days after the shooting, Florida's House of Representatives voted down a motion to take up a bill that would ban assault rifles by 36-71, effectively killing the measure for this session.
On Monday, the White House said Mr Trump would be supportive of proposals to improve background checks before gun purchases.