Beijing could resort to military conflict with self-ruled Taiwan to divert domestic pressure if a slowdown in the world's second largest economy amid a trade war threatens the legitimacy of the Chinese Communist Party, the island's foreign minister has said.

As Taiwan's presidential elections approach in January, China has stepped up a campaign to "reunify" with what it considers a wayward province, wooing away the island's few diplomatic allies and flying regular bomber patrols around it.

In an interview, Taiwan's Foreign Minister Joseph Wu drew attention to China's slowing economy amid its bitter trade war with the United States.