The United States has called on China and Japan to exercise restraint and act responsibly to avoid having the escalating tensions over their territorial dispute affect global economic growth.
The comment from Daniel Russel, US assistant secretary of state for East Asian and Pacific affairs, came just after the Chinese military told Washington not to support Japan over the disputed Diaoyu Islands, known as the Senkakus in Japan.
Russel, wrapping up his meetings in Beijing with diplomats and Lieutenant General Wang Guanzhong - the People's Liberation Army's deputy chief of general staff - said it was in the world's interest for tensions between Tokyo and Beijing to cool.
"The global economy is too fragile and the world's interest in economic growth and stability is too strong for the world's second- and third-largest economy to remain at odds," Russel said at a press briefing.
"We hope leaders on all sides will exercise restraint and sensitivity and will consistently pursue diplomatic, friendly moves to manage disputes or resolve outstanding issues," he said.
Aircraft and ships from Japan and China have conducted rival maritime activities in the vicinity of the islands in recent months, raising fears of conflict, one that could perhaps be sparked by an accident.
Russel said that while the US did not take sides on sovereignty issues, it was not "neutral on matters of responsible behaviour at the sea".
"It is of great concern to the US, as it is to all countries that rely on maritime corridors, that there is any risk of an incident that could lead to a crisis or lead to an escalation," he said.
Washington hoped that the engagement of President Xi Jinping and Japanese Prime Minister Shinzo Abe on the sidelines of the G20 summit in St Petersburg earlier this month would bear fruit, he added.
"It is certainly my hope that both countries remain committed to their policy of mutual and beneficial partnership and act on the basis of their existing bilateral commitments," he said.
Russel also discussed North Korean nuclear issues and the Syrian crisis. China and the US say it is unacceptable for Pyongyang to pursue nuclear weapons.