China on Monday lodged strong protests to Japan over violations of the one-China policy related to Tokyo's anniversary commemoration of its devastating earthquake.

"After the major earthquake and tsunami hit Japan on March 11, 2011, the Chinese government and people conveyed its sympathy and support to the Japanese people," Foreign Ministry spokeswoman Hua Chunying said in an interview on Monday.

During Monday's ceremonies, the Japanese government invited representatives from foreign countries and regions, media organizations reported. Staff members of the Taipei Economic and Cultural Representative Office in Japan were also invited.

Tokyo arranged the personnel from Taiwan to attend the ceremony as part of a diplomatic delegation and international organization's staff, the spokeswoman said.

The move is against principles and the spirit of the 1972 Joint Communique of the Government of the People's Republic of China and the Japanese government, as well as Japan's promises on upholding the one-China policy, Hua said.

Japan has made promises to endorse the one-China policy in key bilateral political documents with China, including the Joint Communique, which both countries signed on Sept 29, 1972.

The Japanese government "fully understands and respects" the Chinese government's position that Taiwan is an inalienable part of the territory of the People's Republic of China, according to the Joint Communique, a landmark of the two Asian neighbors' decision to normalize diplomatic ties in 1972.

"We have lodged solemn representations to Japan and are strongly dissatisfied with Japan's acts," Hua said in a statement on Monday.

She reiterated that the Chinese government resolutely opposes any attempt by word or deed to create "two Chinas" or "one China, one Taiwan".

"We urge Japan to correct the mistake and keep its promises," Hua said.

Ties between China and Japan have been severely strained since the Japanese government illegally "purchased" part of China's Diaoyu Islands in September, a provocation that prompted strong protests from China and an enduring standoff regarding the islands in the East China Sea.

Experts said Tokyo's ceremonial arrangement on Monday added to the strain between the two countries.

Feng Zhaokui, a senior fellow on Japanese studies at the Chinese Academy of Social Sciences, said the relationship now desperately needs to "lower the fever".

In another development on Monday, the Foreign Ministry denied Japanese media reports that a former Chinese senior diplomat is planning to visit Japan. Japanese media reported that Tang Jiaxuan, a former state councilor, plans to visit Japan during the fourth session of the fifth China-Japan Friendship Committee for the 21st Century in late March to chair a committee meeting.

"The reports are untrue," Hua said.

Both countries have maintained communication about the committee's fourth session, Hua said. But "as far as I'm concerned, the schedule for the meeting has not been settled", she said.

Xinhua contributed to this story.