US President Joe Biden calling Chinese President Xi Jinping a "dictator" seriously violated China's political dignity and amounted to public political provocation, China's foreign ministry said on Wednesday.
China expressed strong dissatisfaction and firm opposition, ministry spokesperson Mao Ning said at the regular news conference.
Biden made the remarks at a fundraiser in California on Tuesday, a day after US Secretary of State Antony Blinken met Xi on a trip to China that was aimed at easing tensions between the two countries.
The Kremlin also said that Biden's reference to his Chinese counterpart Xi Jinping as a "dictator," showed the contradictions and unpredictability of US foreign policy.
Kremlin spokesman Dmitry Peskov told reporters that Russia had "bad" relations with Washington and "very good" ties with China.