Tensions have flashed numerous times in recent years over the islands, including face-offs between Japanese and Chinese air and naval forces that have been termed dangerous by both sides.
China responded quickly to the US stance on the disputed islands, saying it brings instability to the region.
“Diaoyu and its affiliated islands have been Chinese territory since ancient times. These are historical facts that cannot be changed. The so-called US-Japan security treaty was a product of the Cold War, and it should not harm China’s territorial sovereignty and legitimate rights,” Chinese Foreign Ministry spokesman Lu Kang said in a statement.
“We urge the US side to adopt a responsible attitude and stop making wrong remarks on the issue of the sovereignty of Diaoyu Islands,” Lu said.
Mattis’ visit to Japan and South Korea follows a campaign in which President Donald Trump unsettled the region by suggesting that Seoul and Tokyo develop their own nuclear …