Image caption Google's chairman, Eric Schmidt has not yet commented on the forthcoming trip

The US state department has said a planned visit to North Korea by Google chairman Eric Schmidt is unhelpful.

The reason for the trip has not yet been revealed, but reports say it is part of a humanitarian mission led by US politician Bill Richardson.

State department spokeswoman Victoria Nuland said: "We don't think the timing of this is particularly helpful."

Ms Nuland added that Mr Schmidt and Mr Richardson were "well aware" of the US government's views.

Mr Richardson, a former governor of New Mexico, has been involved in ad-hoc negotiations with the North Koreans in the last 20 years and has helped in securing the release of US nationals detained by Pyongyang.

Last month, North Korea arrested a US citizen of Korean origin, Pae Jun Ho, for unspecified alleged crimes.

Google is present in neighbouring China, where it was involved in lengthy negotiations over internet access before it effectively shut down its Chinese search engine in 2010.

Internet use is highly restricted in North Korea, where few people have access to a computer and most users can only access a national intranet rather than the world wide web.

Some analysts speculated that for Google's Eric Schmidt the trip could have strategic reasons.

"I think this is part of Google's broader vision to bring the Internet to the world, and North Korea is the last frontier," said Peter Beck, of South Korean's non-profit Asia Foundation, to Reuters.

Google has refused to comment so far.

Image caption Kim Jong-un said 2013 would be a year of creations and changes

Confirmation of Mr Schmidt's trip came days after the North Korean leader, Kim Jong-un, delivered a new year's message on state TV, the first such broadcast for 19 years.

Kim Jong-un, in power since 2011, spoke of the need to improve the economy and also to reunify the Koreas, warning that confrontation only led to war.

Kim Jong-un said 2013 would be a year of creations and changes, calling for a "radical turnabout" that would transform the impoverished, isolated state into an "economic giant" and raise living standards.

But while he said confrontation between the North and the South should be removed, Mr Kim stressed that military power remained a national priority.

Under Mr Kim's leadership, North Korea has conducted two long-range rocket launches - actions condemned by the US and Pyongyang's neighbours as banned tests of missile technology.

The launch in April failed, but December's attempt appears to have been a success, placing a satellite into orbit.

The US, Japan and South Korea are seeking a response in the UN Security Council, which banned North Korea from missile tests after nuclear tests in 2006 and 2009.