Donald Trump is annoyed at the backlash against his phone conversation with Tsai Ing-wen, the leader of Taiwan, who is desperate for support from the United States in her cross-Straits standoff with the Chinese mainland.

The United States president-elect sought to defend himself on Friday on Twitter, saying: Tsai called him, not vice versa; and he saw nothing wrong with receiving a congratulatory call from Taiwan, which buys billions of dollars of US weapons.

In other words, it was a courtesy, and he values the island as a business partner.