China has urged the United States not to interfere in its sovereignty disputes with Japan.
The move comes after US Defense Secretary James Mattis reaffirmed Washington's commitment to defending Japanese territory.
"We urge the US side to take a responsible attitude, stop making wrong remarks on the issue involving the Diaoyu Islands sovereignty, and avoid making the issue more complicated and bringing instability to the regional situation," said Chinese Foreign Ministry spokesperson Lu Kang, as cited by official news agency Xinhua late Friday.
Beijing and Tokyo are involved in sovereignty disputes over the Diaoyu Islands, known as Senkaku in Japan, in the East China Sea.
During Mattis' trip to Japan on Friday - the first visit made by a member of Donald Trump's cabinet - he reiterated the US' commitment to defending territories under Japanese control, including the disputed islands, according to Japanese media.
The sovereignty dispute over the Senkaku Islands, administered by Tokyo, has intensified since Japan nationalized three islets in 2012.
The uninhabited archipelago occupies some 7 square kilometers (2.7 square miles) and the surrounding waters are believed to hold significant reserves of oil and gas.
