The former governor of the state of New Mexico in the United States, Bill Richardson, and Google Chairman Eric Schmidt will travel to the Democratic People's Republic of Korea next week on a "private humanitarian mission", Richardson's office said.

Richardson, a veteran troubleshooter on the DPRK, will hold a news conference at Beijing airport on Thursday, his office said in a statement on Saturday, adding that no journalists would be accompanying the delegation.

The US State Department has voiced concern about the trip, and said it is ill-timed coming after Pyongyang's rocket launch last month.