U
Mark Wilson/Getty Images
Trump rattled the Sino-US relationship after his inauguration by breaking with decades of US policy and taking a call from Taiwanese President Tsai Ing-Wen in December.
The "One China" policy, which the US and China agreed to in 1972, holds that China and Taiwan both belong to a single country. Many on the island of Taiwan, officially known as the Republic of China, see themselves as the legitimate government-in-exile of all of China after the Communist Party took control of the mainland.
For that reason, recognition of Taiwan internationally poses an existential threat to China. China has warned Trump that the "One China" policy between the US and China was non negotiable.