US President Joe Biden has signed the most sweeping gun violence Bill in decades, a bipartisan compromise that seemed unimaginable until a recent series of mass shootings.

In the wake of the latest shooting, which saw the massacre of 19 children and two teachers at a Texas primary school, Mr Biden declared the legislation will mean “lives will be saved”.

Speaking at the White House and citing the families of shooting victims, Mr Biden said: “Their message to us was to do something. Well today, we did.”

The House gave final approval of the Bill on Friday, following Senate passage on Thursday, and Mr Biden acted just before leaving Washington for two summits in Europe.

“Today we say, ‘More than enough’,” Mr Biden said.

“It’s time, when it seems impossible to get anything done in Washington, we are doing something consequential.”

The legislation will toughen background checks for the youngest gun buyers, keep firearms from more domestic violence offenders, and help states put in place red flag laws that make it easier for authorities to take weapons from people adjudged to be dangerous.

The president called it “a historic achievement”.

Most of its 13 billion US dollar (£10.5 billion) cost will help bolster mental health programmes and aid schools, which have been targeted in Newtown, Connecticut, and Parkland, Florida, and elsewhere in mass shootings.

Mr Biden said the compromise hammered out by a bipartisan group of senators “doesn’t do everything I want” but “it does include actions I’ve long called for that are going to save lives”.

“I know there’s much more work to do, and I’m never going to give up, but this is a monumental day,” said the president, who was joined by his wife Jill, a teacher, for the signing.

After sitting to sign the bill, Mr Biden sat reflectively for a moment, then murmured: “God willing, this is gonna save a lot of lives.”

He also said they will host an event on July 11 for legislators and families affected by gun violence.

The president spoke of families “who lost their souls to an epidemic of gun violence. They lost their child, their husband, their wife. Nothing is going to fill that void in their hearts. But they led the way so other families will not have the experience and the pain and trauma that they had to live through”.

Mr Biden signed the measure two days after the Supreme Court’s ruling on Thursday striking down a New York law that restricted people’s ability to carry concealed weapons.

And Saturday’s ceremony came less than 24 hours after the high court overturned the Roe v Wade decision, which had legalised abortion nationwide for nearly five decades.

“Yesterday, I spoke about the Supreme Court’s shocking decision striking down Roe v Wade,” Mr Biden said.

“Jill and I know how painful and devastating the decision is for so many Americans. I mean so many Americans.”

He noted that the abortion ruling leaves enforcement up to the states, some of which have already moved to ban abortion or will soon do so.

Mr Biden said his administration will “focus on how they administer it and whether or not they violate other laws, like deciding to not allow people to cross state lines to get health services”.

Asked by reporters about whether the Supreme Court was broken, Mr Biden said: “I think the Supreme Court has made some terrible decisions.”

He walked away without answering more questions, noting: “I have a helicopter waiting for me to take off.”

While the new gun law does not include the tougher restrictions that Democrats have long championed, such as a ban on assault-type weapons and background checks for all gun transactions, it is the most impactful firearms violence measure from Congress since enacting a now-expired assault weapons ban in 1993.

Enough congressional Republicans joined Democrats in supporting the Bill after recent gun rampages in Buffalo, New York and Uvalde, Texas.

It took weeks of closed-door talks but senators emerged with a compromise.

Mr Biden held the signing ceremony just before departing for a summit of the G7 in Germany. He will then travel to Spain for a Nato meeting.