Prime Minister Theresa May has said she expects Americans to question whether their gun controls are tough enough after the deadliest shooting massacre in US modern history.
The ease with which Las Vegas gunman Stephen Paddock built up and transported his deadly arsenal has again brought the US laws into question.
Mrs May told ITV's Good Morning Britain the attack contrasted sharply with the UK's gun laws, which were toughened after 1996's Dunblane school massacre.
Paddock did not need to register any of the dozens of guns in his arsenal, and there were no limits to the amount of ammunition he could acquire.
Mrs May told Good Morning Britain: "I understand this individual had a very significant arsenal of weapons with him in the hotel from which he was firing and I understand another significant arsenal back at home.
Video report by ITV News Correspondent Angus Walker
"Obviously it's a direct contrast with this country where we have very tough gun laws."
The state of Nevada has some of the softest gun laws in the United States.
Licences are needed for fishing, hunting, driving a car and piloting an aircraft - but not for owning a firearm.
"I think it's up to America what gun laws they put in place," Mrs May said, but added: "Most people would look at this and assume that people in America would be so shocked at this attack that they would want to take some action."
New restrictions on the right to bear arms are unlikely to happen due to the pull the National Rifle Association commands in US politics and with a pro-gun president in Donald Trump.
Many thought the slaughter of 26 people, including 20 children, during a mass shooting at Sandy Hook Elementary School in Connecticut in 2012 would change peoples' minds.
Then-US President Barack Obama was unable to hold back tears as he spoke about the youngest victims of the shootings, and urged Congress to tighten laws.
But firearm sales went through the roof, with many gun owners worried there would be new restrictions brought in.
At the time Mr Trump sent a tweet supporting Mr Obama's comments, but after accepting a nomination from the NRA last year during his presidential campaign, it seemed unlikely gun reform would be on the top of the new president's to-do list.
A proposal requiring background checks on commercial gun sales was blocked in the Senate in April 2013. The House also voted against a ban on assault weapons.
In 2016 four separate gun measures backed by the Obama administration were rejected, and this week Congress will vote on deregulating gun silencers.
Reacting to the Las Vegas attack, White House Press Secretary Sarah Huckabee Sanders made it clear where Mr Trump stood on the issue.
"The president has been clear that he is a strong supporter of the Second Amendment, and I don't have anything to add at this point," she replied when quizzed on potential gun policy changes.
"There’s a time and place for a political debate, but now is the time to unite as a country."