On Saturday, China's foreign ministry spokesman Geng Shuang issued a statement that said 'there is only one China in the world'.
'We have noticed relevant reports and lodged solemn representation with the relevant side in the United States,' Shuang's statement reads.
'I must point out that there is only one China in the world and Taiwan is an inseparable part of the Chinese territory ... The 'one China' principle is the political foundation of China-US relations.
'We urge the relevant side in the US to adhere to the 'one China' policy, abide by the pledges in the three joint China-US communiques, and handle issues related to Taiwan carefully and properly to avoid causing unnecessary interference to the overall China-U.S. relationship.'
The 'One China' policy holds that Washington, while maintaining unofficial relations with Taiwan, does not recognize it as its own nation and therefore does not acknowledge its leaders as heads of state.
The dispute between Taiwan and Beijing began when the losing side of China's 1949 Civil War fled to the island and continued to declare itself the rightful rulers of China. Military tensions have existed between the communist regime and Taipei ever since.
Trump's opponents were quick to claim his phone call risked angering Beijing by seemingly disregarding decades of protocol built on America's acknowledgment of the 'One China' policy.