The 6-3 ruling, with the court's conservative justices in the majority and liberal justices in dissent, struck down New York state's limits on carrying concealed handguns outside the home. The court found that the law, enacted in 1913, violated a person's right to "keep and bear arms" under the U.S. Constitution's Second Amendment.
The ruling, authored by Justice Clarence Thomas, declared that the Constitution protects "an individual's right to carry a handgun for self-defence outside the home."
Thomas added: "We know of no other constitutional right that an individual may exercise only after demonstrating to government officers some special need."
The justices overturned a lower court ruling throwing out a challenge to the law by two gun owners and the New York affiliate of the National Rifle Association, an influential gun rights group closely aligned with Republicans.
The ruling could undermine similar restrictions in other states and imperil other types of state and local firearms restrictions nationwide.
Gun rights, held dear by many Americans and promised by the country's 18th-century founders, are a contentious issue in a nation with high levels of firearms violence including numerous mass shootings.
The United States has experienced hundreds of deaths from dozens of mass shootings in recent years. Just in recent weeks, 19 children and two teachers were killed on May 24 at an elementary school in Uvalde, Texas, and 10 people were slain on May 14 at a grocery store in Buffalo, New York.
President Joe Biden, who has called gun violence a national embarrassment, called the ruling a 'bad decision' at the White House.
"I am disappointed in the Supreme Court gun decision," Biden said. "I think it's a bad decision. I think it's not reasoned accurately, but I'm disappointed."
New York Governor Kathy Hochul at a news conference called the U.S. Supreme Court's ruling on concealed handguns "reprehensible" and “frightful in its scope”.
"We don't need more guns on our streets. We're already dealing with a major gun violence crisis. We don't need to add more fuel to this fire," she said. "Today, the Supreme Court is sending us backwards in our efforts to protect families and prevent gun violence."
The Governor added that the ruling "could place millions of New Yorkers in harm's way. And this is at a time when we're still mourning the loss of lives."
New York City Mayor Eric Adams said officials will review licensing policies and how sensitive locations are defined,
"We cannot allow New York to become the wild, wild west," Adams said. "We will work together to limit the risk this decision will create once it is implemented."
New York City Council made an announcement on measures it hopes can protect New York City from a drastic increase in the proliferation of guns being carried in public spaces.
"Our proposed solution encourages the state to tailor a law that accounts for New York City's high population density as a factor in establishing specific parameters for the designation of sensitive areas where legal firearms are prohibited from being carried by members of the public," said New York City Council speaker Adrienne Adams. "Given the high density that characterizes most of New York City, we need to significantly limit the harm that this court decision could otherwise have in making our streets more reflective of an environment typical of the Wild West, one where concealed gun carrying is the norm all around us."
Adams said the resolution urges the state legislation to designate hospitals and medical facilities, parks and parks department facilities, government buildings and facilities, public and private education buildings and facilities, child care facilities, places of worship, cemeteries, financial institutions, theatres, establishments where alcohol is served, libraries, homeless shelters, mass transit systems and the courts as sensitive areas where illegal firearms would be prohibited within 1000 feet.
Under the New York law's "proper cause" requirement, applicants seeking unrestricted concealed carry permits must convince the state firearms licensing officers of an actual, rather than speculative, need for self-defence. Officials could also grant licenses restricted to certain activities, such as hunting or target practice.
The ruling said that New York's concealed firearm regime is at odds with the text and history of the Second Amendment and how gun rights were protected throughout U.S. history.
New Yorkers called the Supreme Court's gun ruling "dangerous" and "nuts."
"It's going to be chaos," said Aimee Baptiste, outside of the New York Public Library in the Midtown Manhattan neighbourhood of New York City.
"I think they're a little bit deaf to what's going on in the world right now," said Justin Cole. "It used to be that Supreme Court decisions came out and they had people who just thought about what the law was. And it wasn't very divided ideologically. It's kind of scary to think about what's next."
"The only way for things to actually reform and change is if there are more protocols for people to get guns," said Nancy Charriez. "I think there is a need for the Second Amendment, but I think there need to be more regulations on how and when people get them."
David Hogg, a survivor of the 2018 Parkland, Florida, high school shooting and a gun-control activist, believes the declaration by the U.S. Supreme Court stating that the U.S. Constitution protects an individual's right to carry a handgun in public for self-defence is a win for 'bad guys with guns and the gun industry.'
"No, I don't think this is a win for Second Amendment lovers. I think this is a win for the gun industry. I support the Second Amendment. I've been shooting guns since I was in fourth grade... this grotesque misinterpretation of the Second Amendment that is only meant to sell more guns instead of promoting a well-regulated militia," Hogg told Reuters.
Hogg is adamant when it comes to the consequences of the court ruling: "This will lead to more shootings. This will kill young people. It will kill old people. And it will endanger people's lives, including the lives of those on the Supreme Court."
"It's heartbreaking that this happened so close to Uvalde," Hogg said.