China has officially protested Japan's decision to allow Taiwan's former leader to visit.
Vice Foreign Minister Wu Dawei summoned Japan's Ambassador to China Koreshige Anami Wednesday.
Foreign Ministry Spokesman Liu Jianchao told reporters in Beijing Thursday that the subject was former Taiwan president Lee Teng-hui's visit to Japan.
Mr. Liu says China expressed its strongest dissatisfaction and strongest protest to Japan.
China calls Mr. Lee a "top representative" of independence forces in Taiwan. Beijing argues that by allowing Mr. Lee into Japan, Tokyo is encouraging Taiwan independence activities.
China considers the self-governed democratic island part of its territory, which must be reunited at some point with the communist mainland.
As Taiwan's president from 1988 to 2000, Mr. Lee angered Beijing by advocating what he called "state-to-state" relations with China, rather than Beijing's insistence that Taiwan is part of one China.
Japan has said it does not support Taiwan independence and there are no grounds to prevent Mr. Lee's private visit. Mr. Lee studied in Japan in his youth and is expected to arrive in Nagoya on Monday.
Beijing routinely opposes visits, private or official, of current or former Taiwan leaders in countries that have diplomatic ties with China.
Mr. Lee's 1995 visit to the United States led to the Taiwan Strait crisis. China conducted a series of missile tests in the strait before Mr. Lee's 1996 re-election. The United States, which has pledged to defend Taiwan, responded by sending two naval battle groups to the area in a tense show of force before the situation was diffused.