The president spoke at the Newtown High School after meeting privately with families of the victims and emergency personnel who responded to the deadly shootings on Friday inside the Sandy Hook Elementary School in Newtown, Conn, reports FoxNews.com.
"I'll use whatever power this office holds to engage my fellow citizens," he said, "in an effort aimed at preventing more tragedies like this. Because what choice do we have?"
Obama said the nation is failing at what he called "our first task," which he said was to care for the children of the nation.
"It's our first job. If we don't get that right, we don't get anything right," he said, asking: "Can we truly say, as a nation, that we are meeting our obligations? Can we honestly say that we are doing enough to keep our children - all of them - safe from harm?"
Law enforcement officials said Adam Lanza, the gunman, who ended his killing spree by turning the gun on himself, had dawned combat gear and was armed with semiautomatic pistols and a semiautomatic rifle.
The gunman who slaughtered 26 people at the US school had forced his way into the building before he went about brutally shooting young children, some of whom hid in closets and barricaded themselves in bathrooms out of terror, police said. As police searched for the motive that led the 20-year-old man first kill his mother and then innocent children at the Connecticut elementary school, details emerging about the man indicated he suffered from a personality disorder.
"The victims have been positively identified," Lt J Paul Vance, a spokesman for the Connecticut State Police, told the media. Vance did not give further details but said valuable information had been found at the gunman's home, according to the New York Times.
(With inputs from PTI)