North Korea has announced that the Chinese Prime Minister Wen Jiabao is to visit Pyongyang next week. The official North Korean news agency described Mr. Wen's trip as an official goodwill visit, but correspondents say it would take place at a time of increasing efforts to persuade Pyongyang to rejoin the six-country talks on its nuclear programme. North Korea had walked out of the six-party talks after the United Nations condemned its long range missile launch in April.<br/>