US Secretary of State Mike Pompeo said Saturday Washington would lift "complex internal restrictions" on contacts with Taipei by diplomats, after a year of mounting US-Chinese friction on topics including human rights, trade and the origins of the Covid-19 pandemic.
Beijing says Taiwan is an inviolable part of China to be reclaimed, by force if necessary, and opposes any diplomatic recognition of the democratic island.
Chinese foreign ministry spokesman Zhao Lijian said Beijing "strongly condemns" the move and accused the United States of violating the terms of Washington's diplomatic relations with Beijing.
"Any action that harms China's core interests will receive a resolute counterstrike from China," Zhao warned, urging Pompeo to retract the decision or face "severe punishment".
It was not clear what the change means in practice, with Pompeo saying executive branch communications with Taiwan will be handled by the American Institute in Taiwan (AIT), which is owned by the US government and serves as the de facto embassy.