"President Obama rightly sent his heartfelt condolences to the families in Newtown," Bloomberg said in a statement. "But the country needs him to send a bill to Congress to fix this problem. Calling for 'meaningful action' is not enough. We need immediate action."
Obama pledged to address gun violence in similarly general terms in January 2011, when he spoke at a memorial service for six people fatally shot in a supermarket parking lot in Tucson, Ariz. Thirteen other people were wounded in the incident, including then-Rep. Gabrielle Giffords, D-Ariz.
"We cannot and will not be passive in the face of such violence," Obama said that night. "We should be willing to challenge old assumptions in order to lessen the prospects of such violence in the future."
But Obama rarely spoke of the issue on the campaign trail. In July, four months before Election Day, a gunman opened fire with an assault rifle in an Aurora, Colo., movie theater, killing 12 people and injuring nearly 60 others.
Soon after, Obama called for a "common-sense approach" to regulate assault-rifle sales. Speaking to the National Urban League, Obama said, "I, like most Americans, believe that the Second Amendment guarantees an individual the right to bear arms."
"But," he added, "I also believe that a lot of gun owners would agree that AK-47s belong in the hands of soldiers, not in the hands of criminals."
So far, though, his administration has not proposed any measures to accomplish that goal.
Before Obama spoke in midafternoon, Carney told reporters that there would be "a day for discussion of the usual Washington policy debates, but I don't think today is that day."
Gun-control advocates launched a petition drive on the White House website Friday that garnered 20,000 signatures by late afternoon, while demonstrators formed a candlelight vigil outside Obama's residence. "Mr. President, we are praying for your action," read one sign. "Enough is enough," read another.