National Security Adviser John Bolton acknowledged that he has spent years trying and failing to denuclearize North Korea.

"Do you believe North Korea is about to launch a rocket, a missile, a satellite?" ABC's Martha Raddatz asked Bolton on Sunday.

"I'd rather not get into specifics," Bolton replied. "We've seen a lot in North Korea, we watch it constantly. I've been doing this since the first Bush administration -- George H. W. Bush."

"There's a lot of activity going on all the time in North Korea, but I'm not going to speculate," he added.