WASHINGTON (December 17, 2012)--President Barack Obama is vowing to use "whatever power this office holds" to safeguard the nation's children, raising the prospect that he will pursue policy changes to stem gun violence after the elementary school massacre in Newtown, Conn.

Mr. Obama offered few specifics during his remarks at a vigil in Newtown, Conn., Sunday night.

He said he will engage with law enforcement, mental health professionals, parents and educators in the coming weeks.

Friday's shooting, which left 20 children and eight adults dead, appears to have spurred some soul-searching by Mr. Obama who told Connecticut's governor that Friday was the most difficult day of his presidency.

Mr. Obama says he has been reflecting on whether the country is doing enough to give its children "the chance they deserve to live out their lives in happiness."