Former New Mexico Gov. Bill Richardson and Google Chairman Eric Schmidt left Beijing for North Korea on Monday, defying the U.S. government's advice not to visit there.

Diplomatic sources said the delegation departed for Pyongyang on a scheduled Air China flight and the CA121 flight should land at Sunan International Airport later in the afternoon.

In a meeting with reporters at the airport, Richardson made clear that the visit has nothing to do with the U.S. government and that he is not representing Washington. He stressed that the visit is a private visit with a humanitarian purpose.

Richardson, formerly a U.S. ambassador to the U.N., has close personal ties with North Korea and has made several trips there in the past.

He said he wanted to evaluate the humanitarian conditions in the country and meet an American citizen who is being detained in the country.

The politician predicted that getting Kenneth Bae out may be hard, although he had expressed hope for "positive" results before the start of the trip.

He, moreover, said he did not expect to meet North Korean leader Kim Jong-un on this trip, adding the plan is to meet North Korean diplomats, and defense and economic-related officials.

The Korean-American man, who is a tour operator, has been detained in the North for more than two months on a charge of unspecified "hostile acts against the republic."

On concerns raised that his visit came at a bad time, he clarified that he too is worried about North Korea's recent launching of a long-range rocket and hoped the communist country would refrain from carrying out nuclear tests.

Richardson's office confirmed earlier in the day that he will travel to Pyongyang this week "on a private humanitarian mission."

"The delegation will consist of former New Mexico Governor Bill Richardson; Google Executive Chairman Eric Schmidt; Dr. KA Namkung, a Korea affairs advisor to Richardson; and Jared Cohen, the director of Google Ideas, as well as some staff members," it said in an emailed press release.

Since no media is accompanying the delegation, it added, Richardson will have a press availability at the Beijing Airport on Thursday (local time).

The office did not elaborate on the group's itinerary. 

U.S. government officials and South Korean diplomats in Washington remained tight-lipped about it.

Despite such remarks, Richardson's travel to Pyongyang this time, however, has drawn keen attention as he will be accompanied by the Google chairman.

"This is not a Google trip. He's interested in foreign policy, he's a friend of mine, and I felt it was important that there be a broader perspective of our visit, with Eric going and some other members of our staff," Richardson told CBS "This Morning" last week.

The U.S. and South Korean governments, however, take a dim view of their move.

Seoul and Washington are worried that it may send a wrong signal to Pyongyang.

The allies are pushing for tougher U.N. sanctions against North Korea for its long-range rocket launch in December.

The State Department has openly said the timing of the visit is not "helpful."

Meanwhile, a German newspaper reported North Korea is preparing to open up its market to foreign investors.

Pyongyang has received advice from German economists and lawyers for the initiative, according to the Germany daily Frankfurter Allgemeine Zeitung.

The newspaper quoted an unnamed economist involved in the plan as saying, "There is a master plan. They want to open up this year."

The economist said North Korea does not intend to follow the Chinese model, which called for the creation of special economic zones for foreign investors.

"Rather, they are interested in the Vietnamese model, in which specific companies were chosen as recipients of investments," the economist was quoted as saying.

In his verbal New Year's message, North Korea's young-generation leader Kim Jong-un stressed the importance of economic development especially through the science, information and technology fields.

The economist said there are many in the North Korean leadership who are in favor of opening up the country to investments from South Korea, Japanese and Western companies, but an obstacle is the nation's military, which seeks to retain vested powers. (Yonhap News)