TOKYO - China is angry at what it sees as Japan "meddling" in the South China Sea, a think-tank said on Thursday (June 30) in a report urging both countries to establish a hotline to avoid conflict in the East China Sea.
This is but one of several "irritants" that could complicate Sino-Japanese political ties, the International Crisis Group (ICG) said in the 21-page report titled East China Sea - Preventing Clashes from Becoming Crises.
China is embroiled in territorial disputes with Brunei, Malaysia, Philippines, and Vietnam in the South China Sea, and a separate dispute over uninhabited islets known as Diaoyu in Chinese and Senkaku in Japanese in the East China Sea.
Japan is not a claimant in the South China Sea, but has been "one of the most vocal critics of China's actions" there, the ICG said.
It argues it has vital strategic, economic and political interests in the region, and has partnered with the US and South-east Asian countries as part of a "collective response" strategy to counter Beijing in the East China Sea.
"It compares its rival's moves to alter the status quo in the South China Sea, with the Diaoyu/Senkaku dispute," the ICG noted. "By emphasising the importance of rule of law at bilateral and regional venues, Japan frames China's role in that dispute as posing as great a risk to international norms as its South China Sea actions."
Meanwhile, Tokyo is also increasing aid to Vietnam and the Philippines, while supporting US efforts to counter China in the waterway.
And in turn, China has warned Japan not to "over-react" to China's activities in the South China Sea, though the ICG said Japan shows no sign of letting up.
Earlier this week, the Chinese Foreign Ministry urged Japan not to "hype up" the South China Sea issue.
This came after Japanese Vice-Foreign Minister Shinsuke Sugiyama said Japan was "closely watching" the UN arbitration case brought by the Philippines against China. The court is expected to issue a ruling on July 12.
"Some people from the Japanese side have been fanning the flames of tension, and deliberately provoking confrontation among countries in the region," Chinese Foreign Ministry spokesman Hong Lei said.
Separately, Beijing was also irked by Japan's public protests at Chinese resource exploration in the East China Sea last year.
The exclusive economic zones overlap for some 40,000 sq km, and resource development was once a flashpoint in the area.
But the ICG noted that in July 2015, Japan had publicly protested drilling in undisputed Chinese waters, which could have been "driven by domestic calculations".
This had occurred around the time the Japanese Parliament was debating two controversial security Bills as Prime Minister Shinzo Abe sought to reinterpret Article 9 of the pacifist Constitution.
"Mr Abe appeared to calculate that worries over an assertive China would boost his argument for loosening military restrictions," the ICG said in its report.