WASHINGTON - US President Barack Obama said Sunday night that he would use the powers of his office to try and end mass shootings.

The president also said the United States, as a country, is not doing enough to stop such violence.

US President Barack Obama speaks at a vigil held at Newtown High School for families of victims of the Sandy Hook Elementary School shooting in Newtown, Connecticut Dec 16, 2012. Obama is visiting Newtown High School to meet with the families of the victims and to thank first responders to the school shooting here that was one of the deadliest such incidents in the nation's history. [Photo/Agencies]

Speaking at the vigil service for the victims of Sandy Hook Elementary School massacre in Newtown, Connecticut, Obama questioned that "as a nation, are we meeting our obligations? Are we keeping our children, all of them, safe from harm?"

"The answer is no," said Obama. "We are not doing enough...we can't tolerate this any more, these tragedies must end, and to end them we must change."

"In the coming weeks I'll use whatever power this office holds to engage my fellow citizens from law enforcement to mental health professionals to parents and educators in an effort aimed at preventing more tragedies like this," said Obama, stopping short of saying he will push for gun control laws.

Obama flew to Newtown to meet with parents of victims and first responders before he attended a service there for the victims of the shooting.

Adam Lanza, 20-year-old, shot and killed his mother Nancy on Friday, and broke into Sandy Hook Elementary where he killed 20 children and 6 adults, before committing suicide.

Adam Lanza used a semi-automatic rifle to kill most of his victims, shooting each of them multiple times. He also had with him at least 2 pistols. Police said he carried many high-capacity magazines for the rifle.

Toward the end of his speech, Obama read the names of the 20 children killed in the shooting. Audible cries were heard from the audience.

The shooting reignited gun control debate in the United States. California Senator Dianne Feinstein, a top Democrat and leading liberal voice in the Senate, told David Gregory, host of NBC's "Meet the Press" on Sunday that she is reintroducing a federal ban on assault weapons on the first day of the coming Congress, and urged Obama to lead on the issue.

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