U.S. President Barack Obama has set the stage today for a political battle with America's pro-gun advocates.
Obama outlined a series of gun control proposals, in response to last month's school shooting in Newtown, Connecticut.
Obama called for a ban on assault weapons and high-capacity magazines, like the one used in Newtown.
He also called for wider background checks on people who buy guns and urged Congress to approve his $500 million plan.
"To make a real and lasting difference, Congress must act," Obama said. "And Congress must act soon."
"Every day we wait, the number will keep growing," he said.
Obama was joined at the White House by children who wrote him letters after the Newtown shooting, which left 20 children and six teachers dead.
Families of those killed in the shooting, as well as survivors, were also in the audience.
"This is our first task as a society, keeping our children safe," Obama said. "This is how we will be judged."
"If there's even one thing we can do to reduce this violence, if there's even one life that can be saved, then we've got an obligation to try."
Obama called on Congress to:
• bring back a ban on "military-style" assault weapons, which expired when George W. Bush was president
• limit ammunition magazines to 10 rounds
• approve background checks on all gun sales; right now, about 40% are exempt because of a "gun-show loophole." It allows people to buy guns at trade shows and over the Internet without having to undergo a background check.
• make it illegal to possess or sell bullets that can piece armour
• introduce tougher penalties for gun-traffickers, especially unlicensed dealers who buy arms for criminals
Obama said he knows he's in for a tough fight with Congress and pro-gun groups.
"There will be pundits and politicians and special interest lobbyists publicly warning of a tyrannical all-out assault on liberty, not because that's true, but because they want to gin up fear or higher ratings or revenue for themselves," he said.
"And behind the scenes, they'll do everything they can to block any common-sense reform and make sure nothing changes whatsoever."
One of those lobbyists is the NRA, the National Rifle Association. It says it has signed up more than 100,000 members since the Newtown shooting.
It's also just released a video calling Obama "an elitist hypocrite" for allowing Secret Service agents to protect his daughters, when he won't put armed guards in all U.S. schools.
The White House said the ad was "repugnant and cowardly".
Today, Obama pointed out that 900 Americans have been killed by guns since the Newtown shooting one month ago.
"The only way we will be able to change is if their audience, their constituents, their membership says this time must be different, that this time we must do something to protect our communities and our kids," he said.
Obama proposed making money available for schools to hire 1,000 new armed police, school psychologists, or other staff.
He also wants to train more health professionals to deal with young people who may be prone to violence.
As well, Obama signed 23 executive actions, which don't require the approval of Congress. They include:
• Ordering tougher penalties for people who lie on background checks
• Ordering federal agencies to make more information available for background checks
• Requiring federal law enforcement to trace guns that are recovered in criminal investigations
Obama's proposals are based on recommendations from a task force led by Vice-President Joe Biden.
Biden met with gun control and pro-gun advocates, parents of shooting victims, law enforcement officials and people from the entertainment and video game industry.