WASHINGTON: Former New Mexico Gov. Bill Richardson says the U.S. State Department should not be nervous about a visit he's making to North Korea with Google's executive chairman, Eric Schmidt. The former U.N. ambassador calls the mission a private and humanitarian one.

The State Department has advised against the trip. But Richardson says he doesn't work for the U.S. government.

Richardson also said Friday he's concerned about a U.S. citizen detained in North Korea, Kenneth Bae, and has spoken to Bae's son. Richardson points out he has helped negotiate the release of U.S. service members and hostages in the past.

Richardson says he's also concerned about what the U.S. believes is covert North Korean nuclear testing.