China has warned the US against destabilizing East Asia after its new Defense Secretary James Mattis said Washington would rush to defend Japan in case of a conflict with Beijing.
The remarks by China’s Foreign Ministry spokesman Lu Kang on Saturday came after Mattis stated during a two-day official tour of Japan that Senkaku islands fell within the scope of the US-Japan security treaty.
Under the treaty, Washington is obligated to defend all areas under Japanese administrative control, hence making Senkaku which China calls Diaoyu a bone of contention.
"The Diaoyu Island and its adjacent islets have been an inherent part of Chinese territory since ancient times, which is a unchangeable historical fact," state news agency Xinhua quoted Lu as saying.
"We urge the US side to take a responsible attitude, stop making wrong remarks... and avoid making the issue more complicated and bringing instability to the regional situation," he added.
During the visit to Japan, Mattis said, "I made clear that our long-standing policy on the Senkaku Islands stands -- the US will continue to recognize Japanese administration of the islands."
Lu insisted that the US-Japan treaty was a product of the Cold War, and should not affect China's territorial sovereignty, according to the Xinhua’s report.
China cites historical records for its claim, and Japan's move to nationalize several of the islands in 2012 set off anti-Japanese protests across China. The decision prompted the Chinese government to dispatch warships and aircraft to the area as a challenge to Japanese control.
In addition to the new tension over the islands and the South China Sea, China has also slammed a recent pact to deploy a US missile system known as THAAD in South Korea later in the year.