A top Chinese general on Sunday sought to distance the country from claims by some of its scholars that the Ryukyu Islands, which include Okinawa, do not belong to Japan.

Lieutenant General Qi Jianguo, deputy chief of staff of the People's Liberation Army, told a security conference in Singapore that the scholars' views did not represent the official position.

The People's Daily, China's most circulated newspaper, had published an article last month written by two scholars from a top state-run think-tank that argued Beijing may have rights to the Ryukyus.

The lengthy article argued that the island chain was a "vassal state" of China before Japan annexed it in the late 1800s.

"This is only an article of particular scholars and their views on these issues... It does not represent the views of the Chinese government," Qi said at the annual forum known as the Shangri-La Dialogue.

However, he repeated Chinese arguments for China's historical claims over a set of tiny uninhabited islets in the East China Sea known as the Diaoyus in China and Senkakus in Japan.

"I have to say Diaoyu islands and Ryukyu islands and Okinawa islands... the first, and the second and the third, are not the same nature. The Chinese government on this is very clear," he said.

Both countries have been locked in a long-running dispute over the island cluster in the East China Sea which Tokyo administers but is claimed by Beijing.

The two nations have stepped up a war of words in recent months, with Chinese vessels regularly entering waters around the islands, stoking fears of armed conflict.

Some Chinese see historical ties as a basis of sovereignty and dismiss Japan's possession of the islands as a legacy of its aggressive expansionism that ended in defeat at the end of World War II.

Before being annexed into Japan in the late 19th century, the independent Ryukyu kingdom, centred on Okinawa, paid tribute to China for centuries -- as did numerous other traditional Asian states -- often receiving favourable trading rights in return.

Okinawa hosts major US air force and marine bases and is home to 1.3 million people. The US military occupied Okinawa and some other islands in the Ryukyu chain for 27 years after the end of World War II, returning them to Japan on May 15, 1972.