The United States should do nothing to harm China's sovereignty and security in the South China Sea, China's foreign minister told U.S. Secretary of State John Kerry, ahead of a key court ruling on China's claims in the disputed waterway.

Speaking by telephone Wednesday, Chinese Foreign Minister Wang Yi told Kerry the United States should stick to its promises not to take sides in the dispute, China's Foreign Ministry said.

China hopes the United States "speaks and acts cautiously, and take no actions that harm China's sovereignty and security interests," the statement paraphrased Wang as saying.