North Korea's nuclear test last October was a failure and gives no credence to Pyongyang's claim to being a nuclear weapons state, U.S. CIA Director Michael Hayden was quoted as saying by a South Korean newspaper on Wednesday.

North Korea said in October it had successfully conducted an underground nuclear test. U.S. and South Korean officials and experts have said the blast produced a relatively low-yield explosion, and some questioned the North's nuclear capability.

"The United States does not recognize North Korea as a nuclear weapons state," Hayden was quoted as saying by a South Korean defense official in the JoongAng Ilbo newspaper. "It's because the nuclear test last year was a failure."

Hayden was speaking to South Korean Defense Minister Kim Jang-soo on his stop in Seoul as part of visits to South Korea, Japan and China, JoongAng Ilbo said.

South Korea's Defense Ministry declined to confirm Hayden's comments but said Hayden had visited Kim on Tuesday. The U.S. embassy declined to comment.

The test last year led to a U.N. Security Council resolution slapping financial sanctions on Pyongyang.

But North Korea agreed to a breakthrough deal in February with South Korea, the United States, Japan, Russia and China to end its nuclear program in return for aid worth about $330 million.