US President Barack Obama wants "concrete proposals" to curb gun violence by the end of next month in the aftermath of the Newtown school massacre.
He has tasked vice president Joe Biden with co-ordinating the campaign and said he will push legislation "without delay".
The president urged Congress to hold votes on the bill.
Mr Obama says the issue was complex but said: "We have a deep obligation - all of us - to try."
Mr Biden, a long-time gun control advocate, will lead a team that will include members of Mr Obama's administration and outside groups.
The move comes after Friday's shooting at Sandy Hook Elementary in Connecticut. Twenty children and six adults were killed at the school by a gunman with a semi-automatic rifle.
"The fact that this problem is complex can no longer be an excuse for doing nothing," Mr Obama said. "The fact that we can't prevent every act of violence doesn't mean we can't steadily reduce the violence."
Mr Obama, who pushed little on gun control during his first term, also pressed Congress to reinstate an assault weapons ban, which expired in 2004.
He called for stricter background checks for people who seek to purchase weapons and limited high-capacity magazines.
The administration will have to make its gun control push in the middle of tense negotiations with Congress to avoid the ``fiscal cliff'' of billions of dollars in tax increases and deep spending cuts that will kick in at the end of the year without a deal.
Notably, the first question asked of Mr Obama during a press conference after his gun announcement was about the fiscal talks.
In the days since the shooting he has vowed to use “whatever power this office holds” to safeguard the nation’s children.
The shooting has prompted several congressional gun-rights supporters to consider new legislation to control firearms, and there are concerns in the administration and elsewhere that their willingness to engage could fade as the shock and sorrow over the shooting eases.
The most powerful supporter of gun owners and the gun industry, the National Rifle Association, broke its silence four days after the shooting. In a statement, it pledged “to help to make sure this never happens again” and has scheduled a news conference for Friday.
With the NRA promising “meaningful contributions” and Mr Obama vowing “meaningful action”, the challenge in Washington is to turn words into action.
Ideas so far have ranged from banning people from buying more than one gun a month to arming teachers.
The challenge will be striking the right balance with protecting the Second Amendment right to bear arms. Firearms are in a third or more of US households, and suspicion runs deep of an overbearing government whenever it proposes expanding federal authority.
Many pro-gun politicians also have called for a greater focus on mental health issues and the impact of violent entertainment like video games. Mr Obama also prefers a wider approach, with aides saying stricter gun laws alone are not the answer.
Mr Obama said that the US needs to make access to mental health care as easy as access to a gun.
However much of the immediate focus is on gun control, an issue that has been dormant in Washington for years despite several mass shootings.
The policy process Mr Obama announced was expected to include input from the departments of Justice, Education, and Health and Human Services. The Department of Homeland Security is also expected to play a key role.
Pressure for change has come from several sources this week.
As shares in publicly traded gun manufacturers dropped, the largest firearms maker in the United States said it was being put up for sale by its owner, private equity group Cerberus Capital Management, which called the shooting a “watershed event” in the debate over gun control.
Freedom Group International makes Bushmaster rifles, the weapon thought to have been used in Friday’s killings.
In California, proposed legislation would increase the restrictions on purchasing ammunition by requiring buyers to get a permit, undergo a background check and pay a fee.
The US Conference of Mayors wrote to Mr Obama and Congress calling for “stronger gun laws, a reversal of the culture of violence in this country, a commission to examine violence in the nation, and more adequate funding for the mental health system.”
The mayors asked for a ban on assault weapons and other high-capacity magazines, like those reportedly used in the school shooting; a stronger national background check system for gun purchasers; and stronger penalties for straw purchases of guns, in which legal buyers acquire weapons for other people.
Formerly pro-gun Democratic Senate Majority Leader Harry Reid has said “a thoughtful debate about how to change laws” is coming soon. Republican senator Charles Grassley has said the debate must include guns and mental health.
NRA member senator Joe Manchin, a conservative Democrat, said it was time to begin an honest discussion about gun control.