"This is our first task as a society: keeping our children safe," Obama told a packed event attended by some of the families of the victims of last month's mass shooting in Newtown, Conn.
"This is how we will be judged, and their voices should compel us to change ... 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 it."
But he made clear later in his remarks: "The only way we can change is if the American people demand it."
After high-fiving four schoolchildren who wrote him letters pleading with him to do something about gun violence in Newtown's dreadful aftermath, Obama signed 23 executive orders aimed at strengthening background checks for gun purchasers and expanding safety programs in schools.
He also urged Congress to reinstate the ban on assault weapons that expired in 2004, to restrict ammunition magazines to no more than 10 rounds and to require universal background checks on anyone seeking to buy a firearm.
Yet there's scant hope those measures — modest by the standards of most other industrialized nations — will pass Congress. And it's not just Republicans opposed to tougher gun control measures; some Democratic senators have suggested they'll vote against them too.
Senate Majority Leader Harry Reid said this week he doubted an assault weapons ban would pass Congress despite a slate of post-Newtown polls that indicate the majority of Americans are clamouring for tougher gun control laws, particularly regarding assault weapons.
House and Senate committees have said they'll start holding hearings on gun control measures in the coming weeks.
Twenty-seven people died in the carnage in Newtown, including the perpetrator, 20-year-old Adam Lanza.
Lanza used his well-heeled mother's high-powered assault rifle to gun down the woman in her bed before driving to a nearby elementary school to massacre 20 first graders and the five adults who tried to save them.
Just a week following the shooting, NRA executive director Wayne LaPierre held a surreal news conference railing against any efforts to beef up gun control while blaming the media, violent video games and mental illness for the carnage.
Since then, the NRA's fight has been getting increasingly nasty, even though a poll conducted last year suggested the majority of the organization's membership support tougher gun control laws. Nonetheless, the NRA has gained 250,000 new members since Newtown.
Just minutes before Obama and Vice-President Joe Biden took the stage in an auditorium at the Eisenhower Office Building, next door to the White House, the president's press secretary condemned a new ad by the NRA that makes reference to the president's daughters, Malia and Sasha Obama.
"Are the president's kids more important than yours?" the ad asks. "Then why is he skeptical about putting armed security in our schools when his kids are protected by armed guards at their school?"
Jay Carney called the ad "repugnant and cowardly."
But NRA spokesman Andrew Arulanandam says donations are flooding into the organization, warning the Obama administration: "This is going to be a very expensive and hard-fought fight."
The NRA has long insisted it merely advocates for the Second Amendment rights of average American citizens. But in recent years there have been suggestions that the organization receives major funding from gun manufacturers.
The Violence Policy Center, a gun control advocacy group, has estimated that since 2005, gun manufacturers have contributed up to U$38.9 million to the NRA. The NRA doesn't disclose donor information despite spending millions on federal election campaigns.
There are now an estimated 300 million guns in the U.S. and at least one firearm in about 45 per cent of the nation's households.
The affection for firearms is deeply ingrained in the American psyche, due in part to a historic and long-held distrust of government. Early settlers were pioneers and revolutionary rebels, and for many Americans, guns are a symbol of "freedom," particularly in the south and the West.
But gun control advocates insist that the Second Amendment of the U.S. Constitution, enshrining the right to bear arms, has been distorted by gun enthusiasts to a degree never intended by the country's Founding Fathers.
They also point out the Americans should also be free from being gunned down by madmen with legally acquired assault weapons in schools, movie theatres and other public places.
Obama denied his administration has any intention of tinkering with the Second Amendment.
"We can respect the Second Amendment while keeping an irresponsible law-breaking few from inflicting harm on a massive scale," he said.
Nonetheless, his executive orders spurred outrage on social media and among some congressional Republicans.
Steve Stockman, a Texas congressman who's already called for Obama's impeachment over his gun control efforts, assailed the president for inviting children to the news conference.
"He's even using children. It reminds me of Saddam Hussein when he used kids," Stockman told CNN.
On Twitter, there were renewed calls to boot Obama out of office.
"Now is the time to impeach that Marxist dictator Obama," read one tweet among thousands in a similar vein.Suggest a correction