Obama warns North Korea: ‘Bad behavior will not be rewarded’

The president, though, cautioned North Korea's leaders that "bad behavior will not be rewarded."

"There had been a pattern, I think, for decades in which North Korea thought if they had acted provocatively, then somehow they would be bribed into ceasing and desisting acting provocatively," said Obama.

The president also spoke about his visit to the Demilitarized Zone earlier Sunday.

Obama described North Korea as "a time warp." "It's like you're looking across 50 years into a country that has missed 40 years or 50 years of progress," he said.

Obama's visit to the Korean peninsula comes 100 days after the death of long-time North Korean leader Kim Jong Il. Kim, who reportedly died of a heart attack in December, was succeeded by his son Kim Jong Un.

The administration, though, concedes that there are many questions about the younger Kim's grasp on power and the regime's motives.

"It's not clear exactly who is calling the shots and what their long-term objectives are," Obama said of Pyongyang.

North Korea’s planned rocket launch is a setback to international efforts to restart multi-party talks aimed at convincing the regime to abandon its nuclear weapons.

North Korea walked away from talks with the U.S., South Korea, Japan, Russia and China in 2009. In 2011, the U.S. began negotiations with Pyongyang on restarting the six-party talks.