The Diaoyu Islands belong to China since ancient times, former US congressman David Wu said.

The Japanese government's behavior on the issue has brought troubles for the China-US relations and put the Obama administration in a very awkward situation, Wu said in a recent interview with the Hong Kong-based newspaper Wen Hui Po.

Wu, who stated during his term of office that historically and geographically the Diaoyu Islands have always been a part of China, said he still holds this viewpoint and it is unfortunate and unnecessary for the United States to get involved in the issue of the Diaoyu Islands.

It was Shinzo Abe's government which complicated the East China Sea situation and the Japanese prime minister's 2013 visit to the Yasukuni shrine, which enshrines 14 convicted Class-A war criminals, also irritated East Asian countries, Wu said.

Japan has never made enough apologies for what it did during World War II, which has infuriated China and other countries and made unnecessary troubles for the United States, Wu said.

Wu believed the United States does not hope to intensify its relations with China.

He said a lot of companies from America and other countries have made huge investment in China in the past 30 years and that it is likely these countries will receive a great amount of investment from China in the next 30 years.

A peaceful solution to the Diaoyu Islands issue is in the interest of both China and the United States, Wu said.