Chinese State Councilor and Defense Minister General Wei Fenghe speaks during the second round of U.S.-China Diplomatic and Security Dialogue on November 9, 2018 in Washington, DC.

China on Monday called on the U.S. military to stop flexing its muscles in the South China Sea and to avoid adding "new uncertainties" over Taiwan, during high-level talks that underscored tension between the world's two largest economies.

The remarks by Chinese Defense Minister Wei Fenghe to U.S. Defense Secretary Mark Esper, recounted by a Chinese spokesman, came just two weeks after a top White House official denounced Chinese "intimidation" in the busy waterway.

It also came a day after Esper publicly accused Beijing of "increasingly resorting to coercion and intimidation to advance its strategic objectives" in the region.

During closed-door talks on the sidelines of a gathering of defense ministers in Bangkok, Wei urged Esper to "stop flexing muscles in the South China Sea and to not provoke and escalate tensions in the South China Sea," the spokesman, Wu Qian, said.

China claims almost all the energy-rich waters of the South China Sea, where it has established military outposts on artificial islands. However, Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims to parts of the sea.

The United States accuses China of militarizing the South China Sea and trying to intimidate Asian neighbors who might want to exploit trillion of dollars worth of oil and gas reserves.