BEIJING, Feb. 24 (Xinhua) -- China has lodged representations to the Japanese side and urged Japan to be cautious in its words and deeds regarding Taiwan-related issues, a foreign ministry spokesperson said Friday in Beijing.

Spokesperson Geng Shuang's remarks came after a Japanese Defense Ministry think tank released a report on China's security, in which Taiwan was put in parallel with the Chinese mainland as a political entity.

"We have lodged solemn representations to the Japanese side," Geng said, stressing that the Taiwan-related issue, part of the country's domestic affairs, concerned China's core interests.

He urged the Japanese side to abide by the principles set in the 1972 Sino-Japanese Joint Statement, stick to the one-China principle and handle Taiwan-related issues prudently.

According to the joint statement, the Japanese government fully understands and respects the Chinese government's position on Taiwan as an inalienable part of China's territory.

"Japan should refrain from sending the wrong messages to 'Taiwan independence' secessionist forces, undermining regional peace and stability, or causing new disturbances to China-Japan relations," Geng said.