It is unlikely that the United States will be able to influence North Korea to denuclearize, a senior U.S. official said Tuesday, in one of the frankest senior government assessments of U.S. policy goals for the peninsula in decades.

"I think the notion of getting the North Koreans to denuclearize is probably a lost cause," said Director of U.S. National Intelligence James Clapper in an interview with the Council on Foreign Relations (CFR). "They are not going to do that...that is their ticket to survival."