Recalling the shooting rampage that killed 20 first graders as the worst day of his presidency, President Barack Obama on Sunday pledged to put his “full weight” behind legislation aimed at preventing gun violence.

Obama voiced skepticism about the National Rifle Association’s proposal to put armed guards in schools following the Dec. 14 tragedy at Sandy Hook Elementary School in Newtown, Conn. The president made his comments in an interview with NBC’s “Meet the Press.”

Instead, the president vowed to rally the American people around an agenda to limit gun violence, adding that he still supports increased background checks and bans on assault weapons and high-capacity bullet magazines. He left no doubt it will be one of his top priorities next year.

“It is not enough for us to say, ‘This is too hard so we’re not going to try,'” Obama said