Meanwhile, Natsuo Yamaguchi, leader of the pacifistic New Komeito, the junior coalition partner of the ruling Liberal Democratic Party, said on Saturday night that he will take a handwritten letter from Japanese Prime Minister Shinzo Abe to Beijing.

Yamaguchi told reporters after meeting Abe that they both agreed that political talks are the "first step" to mending relations.

Yamaguchi said he hopes to deliver the letter to Party chief Xi Jinping during his four-day visit from Tuesday, Japan's Kyodo News Agency said.

The China-Japan Friendship Association, a non-governmental organization, will host Yamaguchi. It is not clear whether Yamaguchi's proposal of meeting Xi has been confirmed by Beijing.

Shotaro Yachi, a former senior diplomat now advising the Japanese prime minister on foreign policy said in an interview with Reuters that "there must be a tacit understanding between Yamaguchi and the prime minister for seeking improved ties''.

Notwithstanding Abe's proposed letter, Tokyo has not eased off on its attempts to lobby Washington for more support, said Shen Shishun, a specialist on Asia-Pacific studies at Haikou College of Economics in Hainan province.

"Tokyo's seemingly friendly postures are not feasible to resolve the tension,'' Shen warned.

Yamaguchi may press for a summit meeting between leaders of the two countries, Japanese newspaper Mainichi Shimbun said.

However, the Japanese government has long denied the existence of any dispute over the Diaoyu Islands.

The tense situation helps the Abe cabinet shift domestic public attention from the sluggish economy, said Zhu Feng, a professor of international relations at Peking University.

Shen said Japan has long been "obsessed in its illusion" of maintaining economic ties with China while posing tough on territorial disputes.

Contact the writers at zhangyunbi@chinadaily.com.cn

Pu Zhendong and Xinhua contributed to this story.