WASHINGTON (CBSDC) – President Barack Obama says he still wants to sign gun control legislation before he leaves office and calls it “heart-breaking” his administration hasn’t done so yet.

The president told ABC News’s Dr. Richard Besser getting tighter restrictions on guns has been incredibly difficult.

“What we’ve done is to try to do as much as we could administratively to tighten up how background checks are run, to go after illegal drug runners,” Obama told ABC News. “But I will tell you that trying to get something through Congress has proven to be very difficult. And it’s heart-breaking.”

Getting tougher gun laws on the books was a stated priority in the weeks and months after the Sandy Hook Elementary School shooting in December 2012 where 26 people were killed, including 20 children.

“You know, those two or three days after the Sandy Hook shooting are some of the worst days of my presidency because I met those families right after,” Obama told ABC News. “And you’re talking about 6-year-olds who were just systematically murdered. And that may be one of the few times where I was just shocked that Congress didn’t act.”

The president puts part of the blame for the lack of action on the National Rifle Association.

“But the power of NRA and the gun lobby in Congress is formidable,” Obama said. “And you know, we’re going to keep chipping away at this, but until you get intense public demands for this, it’s probably not going to happen because some special interests and lobbyists in Washington are really, really strong and their membership feels very intensely about the issue. Whereas the general public is concerned about it, but doesn’t make it their top priority.”