North Korean leader Kim Jong-il is expected to visit a major commercial city in China before heading to Beijing.

Diplomatic sources on Wednesday said Kim could tour Shanghai, Shenzhen or Suzhou in an attempt to weather U.S. financial sanctions over the North's alleged counterfeiting and show interest in China's economic reforms.

His whereabouts and destinations are shrouded in mystery, with Reuters quoting a source as saying Kim only passed through China on his way to Russia and did not meet with Chinese leaders.

In Seoul, Foreign Minister Ban Ki-moon said Beijing has said nothing to Seoul of Kim's visit to China.