China has condemned the United States for lifting self-imposed restrictions on contacts between US officials and their counterparts in Taiwan.
Chinese foreign ministry spokesperson Zhao Lijian said on Monday that China will not permit any person or force to stop the process of China's reunification.
His remarks came after US Secretary of State Mike Pompeo announced the change on Saturday.
Zhao said the Taiwan question remains the most important and sensitive issue at the core of China-US relations. He urged the US to stop elevating relations and military ties with Taiwan.
China's Taiwan Affairs Office of the State Council said that China "will take strong countermeasures against any collusion" between the US and Taiwan.
China is apparently wary of a recent rapprochement between the US and Taiwan. US Ambassador to the United Nations Kelly Craft is expected to visit Taiwan on Wednesday.