President Barack Obama, speaking alone on a spare stage for a nation in sorrow, declared Sunday that he will use “whatever power” he has to prevent shootings like the Connecticut school massacre.

“What choice do we have?” Obama said at an evening vigil in the shattered community of Newtown, Connecticut. “Are we really prepared to say that we're powerless in the face of such carnage, that the politics are too hard? Are we prepared to say that such violence visited on our children year after year after year is somehow the price of our freedom?”

For Obama, that was an unmistakable sign that he would at least attempt to take on the explosive issue of gun control. He made clear that the deaths compelled the United States to act, and that he was the leader of a nation that was failing to keep its children safe. He spoke of a broader effort, never outlining exactly what he would push for, but expressed outrage by yet another shooting rampage.

“Surely we can do better than this,” he said. “We have an obligation to try.”

The massacre of 26 children and adults at Sandy Hook Elementary on Friday elicited horror around the world, soul-searching in the United States, fresh political debate and questions about the incomprehensible _ what drove the 20-year-old suspect to kill his mother and then unleash gunfire on children.

A total of 6 adults and 20 boys and girls ages 6 and 7 were slaughtered.

Obama told Connecticut Gov. Dannel Malloy that Friday was the most difficult day of his presidency. The president has two daughters, Malia and Sasha, who are 14 and 11, respectively.

“Can we say that we're truly doing enough to give all the children of this country the chance they deserve to live out their lives in happiness and with purpose? I've been reflecting on this the last few days,” the president said, somber and steady in his voice. “And if we're honest with ourselves, the answer is no. We're not doing enough and we will have to change.”

He promised in the coming weeks to talk with law enforcement, mental health professionals, parents and educators on an effort to prevent mass shootings.

The shootings have restarted a debate in Washington about what politicians can to do help _ gun control or otherwise. Obama has called for “meaningful action” to prevent killings.

Democratic lawmakers said Sunday that military-style assault weapons should be banned and that a national commission should be established to examine mass shootings in the U.S.

Obama and Senate Democrats haven't pushed for new gun controls since rising to power in the 2008 elections. Outspoken advocates for stricter laws, including Sen. Dianne Feinstein, say that's because of the powerful sway of the National Rifle Association, the gun owners' lobby.

But gun control advocates also say the latest shooting is a tipping point that could change the dynamic of the debate. Feinstein said she will propose legislation next year that would ban big clips, drums and strips of more than 10 bullets.

Near the start of his remarks, Obama read the names of the adults who died. He finished by reading the first names of the kids, slowly, in the most wrenching moment of the night.

Cries and sobs filled the room.

“That's when it really hit home,” said Jose Sabillon, who attended the interfaith memorial with his son, Nick, a fourth-grader who survived the shooting unharmed.

Said Obama of the girls and boys who died: “God has called them all home. For those of us who remain, let us find the strength to carry on and make our country worthy of their memory.”

Inside the room, children held stuffed teddy bears and dogs. The smallest kids sat on their parents' laps.

There were tears and hugs, but also smiles and squeezed arms. Mixed with disbelief was a sense of a community reacquainting itself all at once.

One man said it was less mournful, more familial. Some kids chatted easily with their friends. The adults embraced each other in support.

“We're halfway between grief and hope,” said Curt Brantl, whose daughter was in the library of the elementary school when the shootings occurred. She was not harmed.

The president first met privately with families of the victims and with the emergency personnel who responded to the shootings. The gathering happened at Newtown High School, the site of Sunday night's interfaith vigil, about a mile and a half from where the shootings took place.

Police and firefighters got hugs and standing ovations when they entered. So did Obama.

“We needed this,” said the Rev. Matt Crebbin, senior minister of the Newtown Congregational Church. “We needed to be together to show that we are together and united.”

Police say the gunman, Adam Lanza, was carrying an arsenal of ammunition big enough to kill just about every student in the school if given enough time. He shot himself in the head just as he heard police drawing near, authorities said.

“There was a lot of ammo, a lot of clips,” said state police Lt. Paul Vance. “Certainly a lot of lives were potentially saved.”

The chief medical examiner has said the ammunition was the type designed to break up inside a victim's body and inflict the maximum amount of damage, tearing apart bone and tissue.

A Connecticut official said the gunman's mother was found dead in her pajamas in bed, shot four times in the head with a.22-caliber rifle. The killer then went to the school with guns he took from his mother and began blasting his way through the building.

All the victims at the school were shot with the rifle, at least some of them up close, and all were apparently shot more than once, Chief Medical Examiner Dr. H. Wayne Carver said. There were as many as 11 shots on the bodies he examined.

Investigators have offered no motive for the shooting. A law enforcement official, speaking on condition of anonymity, said investigators are reviewing the contents of Lanza's computer, as well as phone and credit card records in an effort to piece together his activities leading up to the shooting. The official was not authorized to discuss the details of the case.

Obama said his words of comfort would not be enough, but he brought them anyway, on behalf of parents everywhere now holding their children tighter.

“I can only hope that it helps for you to know,” he said, “that you are not alone in your grief.” (AP)