US Vice-President Kamala Harris has made an impassioned plea for a ban on assault weapons in the wake of two deadly mass shootings in the US.
Ms Harris was attending the funeral of Ruth Whitfield, 86, killed in a supermarket in Buffalo on 14 May.
That shooting came just 10 days before an attack on a Texas primary school left 19 children and two teachers dead.
Ms Harris, listing these and other attacks, said it was time to say "enough is enough" to gun violence.
"Everybody's got to stand up and agree that this should not be happening in our country and that we should have the courage to do something about it," she told the congregants at the funeral.
She added that the solution was clear - and included things like background checks and an assault weapons ban.
"Do you know what an assault weapon is?" she asked, continuing: "It was designed for a specific purpose: to kill a lot of human beings quickly. An assault weapon is a weapon of war, with no place, no place in a civil society."
The 18-year-old gunman in Tuesday's shooting in Uvalde had two AR-15-style semi-automatic rifles, at least one of which he is reported to have bought soon after his birthday.
After he was shot dead, police found as many as 1,657 rounds of ammunition and 60 magazines in his possession.
The Buffalo, New York, shooter, also 18, had previously come into contact with authorities, but no red flags came up when he legally bought his own AR-15-style weapon.
"Why should anyone be able to buy a weapon that can kill other human beings without at least knowing, 'Hey, has that person committed a violent crime before? Are they a threat against themselves or others? That's just reasonable," Ms Harris said on Saturday.
However, attempts to bring in universal background checks and bans on assault weapons have hit roadblocks. The issue is divisive in the US, with almost all Democrats backing stronger controls, compared to just 24% of Republicans.
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The powerful National Rifle Association (NRA) gun lobby uses its substantial budget to influence members of Congress on gun policy.
On Friday, former Republican President Donald Trump called not for tighter gun controls, but for better protected schools.
Speaking at the NRA's meeting, he said that decent Americans should be allowed firearms to defend themselves against "evil".
The same day, it emerged police did not enter the classroom in Uvalde, Texas, because of the active shooter inside.
Instead - as children called the emergency services begging for help - they waited 40 minutes, a decision police have now admitted was "wrong".
US President Joe Biden is expected to make his own call for tighter gun controls during a visit to Uvalde on Sunday. On Saturday he urged Americans to "make their voices heard" against gun violence.
Delicate balancing act for Biden
By Will Grant, BBC News, Uvalde
President Biden faces a challenge in striking the right balance in Uvalde. Primarily, he will be there to offer his condolences and sympathy to the victims' families. As someone who has lost children himself, he will be deeply empathetic to their loss.
However, some mourning relatives do not want to see him, or any politician, amid fears their grief may be co-opted into the wider political debate on gun control.
Before travelling to Uvalde, Mr Biden told students in Delaware that it was still possible to "make America safer" but as he seeks cross-party support for tighter gun regulations, he's in direct conflict with leading Republicans who blame the problem on issues of school security and mental health, rather than guns.
As such, meaningful bipartisan co-operation looks very unlikely. Such questions, however, may well be paused for a few hours in Uvalde while he mourns the 21 victims of one of the worst school shootings in US history.