US President Joe Biden on Wednesday promised to go after illegal gun dealers and boost federal funding and support for local law enforcement, after a sharp increase in the number of homicides in large cities.
"Merchants of death are breaking the law for profit," Mr Biden said.
He said the administration would have "zero tolerance" for rogue firearms dealers who broke federal laws.
Mr Biden said the government would help states to employ more police officers, using funds already approved to help the economy recover from the Covid-19 pandemic.
"My message to you is this," Mr Biden said, addressing gun dealers who wilfully break the law.
"We will find you and we'll seek your licence to sell guns. We'll make sure you can't sell death and mayhem on our streets."
The administration will strengthen efforts by the Bureau of Alcohol, Tobacco, Firearms and Explosives to stop gun trafficking across states, Mr Biden and Attorney General Merrick Garland said at the White House, detailing steps the Department of Justice unveiled on Tuesday.
In April, Mr Biden signed executive orders asking the department to crack down on self-assembled "ghost guns".
Such orders allow him to act quickly without waiting for Congress, where Democrats hold a razor-thin majority and Republicans generally oppose gun control legislation.
Gun rights, protected by the Second Amendment of the US Constitution, are among the thorniest political issues in America, where the rate of gun deaths exceeds that of other wealthy countries.
In 2020, homicides in large US cities rose 30 per cent from a year earlier, while gun assaults rose 8 per cent, with the fastest rate in big cities such as Chicago and Houston, the White House said.
It was quoting from a report by the non-partisan research group the Council on Criminal Justice.
Overall, the national rate is still far below the national average in the 1970s or 1980s.
The "precipitous rise in homicides coincided with the emergence of mass protests after George Floyd was killed in late May by a police officer in Minneapolis", the report said.
It said there was "no simple connection" between police violence, protests and community violence.
Property crimes, such as burglary and larceny, fell significantly in 2020.
Mr Biden and Mr Garland met the mayors of Baltimore, Maryland and Rapid City, South Dakota, the police chief of Baton Rouge, Louisiana, and other experts to discuss community safety measures.
The US Treasury Department released information on how states and local authorities could tap into the $350 billion from the American Rescue Plan Act to respond to violent crime, including by investing in community policing.
The administration faces growing impatience from gun-safety activists who want Mr Biden to act faster against gun violence after he campaigned on a pledge to fight the epidemic on his first day in office.
This year, 20,989 Americans have died as a result of gun violence up to June 23, more than half through suicide, said the Gun Violence Archive, a research group.
The Republican Party said Mr Biden's Democratic administration "should have stood up to Democrats" who do not sufficiently support law enforcement.
US gun sales soared in 2020 during the coronavirus pandemic and social unrest over police killings of black people and a contested presidential election.
At the time, some experts said a surge in homicides could be next.
"It's pretty clear that more guns is more death," Harvard University's Prof David Hemenway told Reuters in October.
Meanwhile in New York, Brooklyn Borough President Eric Adams took the lead in the Democratic primary for the city’s mayoral race after promising to reform policing while fighting the city's rising crime levels.
“I’m going to keep my city safe,” Mr Adams told supporters.
After the killing of George Floyd in police custody last year, US progressives have called for police funding cuts as a way to tackle racism.
Still, a message of law and order appears to resonate in cities with rising crime rates, like New York.
While Mr Adams, a former captain in New York’s police department, has an early lead, a new voting system means the final result will not be known for weeks.
The technology entrepreneur Andrew Yang, who rose to national attention in last year’s presidential race, withdrew his candidacy for mayor after a weak performance on Tuesday.
The winner of the Democratic primary is expected to win the November 2 mayoral vote in the left-leaning city.