U.S. Defense Secretary Donald Rumsfeld says average North Korean IQs are feared to be falling due to malnutrition and insufficient diet.

Rumsfeld made the remarks on Thursday during his luncheon speech at the National Press Club in Washington.

The defense secretary also said that the North even conscripts into its military people whose height and weight are less than 147 cm and 45 kg.

Rumsfeld, however, expressed optimism over the six-party nuclear talks, saying that South Korea, the U.S., China, Japan and Russia might someday persuade North Korean leaders to take the same path of disarmament trodden by Libyan leader Muammar Gaddafi.