BEIJING, Sept. 23 (Xinhua) -- China expresses strong dissatisfaction and firm opposition to a joint statement by the United States, Japan and the Republic of Korea (ROK) on Taiwan and maritime affairs, a foreign ministry spokesperson said Tuesday. Spokesperson Guo Jiakun made the remarks at a regular press briefing in response to the statement by the three countries, saying they had interfered in China's internal affairs and sought to slander and defame China. Taiwan is an inalienable part of China's territory, and the Taiwan question is purely China's internal affair that brooks no external interference, Guo added. Guo added that relevant countries should abide by the one-China principle, stop conniving at "Taiwan independence" separatist activities in any form, and refrain from sending wrong signals to "Taiwan independence" separatist forces. He stressed that relevant countries should respect the joint efforts of regional countries to resolve issues and maintain peace and stability through dialogue and consultation, and refrain from stoking tensions or provoking confrontation.