One China policy

His comments came at the end of a five-day visit to Taiwan, where he met with President Tsai Ing-Wen.

Taiwan state media report that on Friday, President Baron Waqa reiterated support for Taipei, and rejected the One China policy.

Nauru is one of a dwindling number of countries recognising Taiwan, which Beijing claims sovereignty over.

Mr Waqa said China's policies were "designed to entice and hook up" countries in the Pacific.

He said Nauru and Taiwan would continue to work together in areas like fishing and medical aid.

Trump has signaled a willingness to confront Beijing, and his latest comments in an interview with Fox News suggested that he won't hesitate to anger China until the country comes to the bargaining table on trade and North Korea.

China's response was measured but clear: co-operation with the US "would be out of the question" if Trump doesn't adhere to the 'one China' policy -- a cornerstone of bilateral relations since the establishment of diplomatic ties in the 1970s.

"I fully understand the 'one China' policy, but I don't know why we have to be bound by a 'one China' policy unless we make a deal with China having to do with other things, including trade," Trump said on "Fox News Sunday."

Trump had set off a diplomatic controversy when he took a call from Taiwan's leader. The United States recognizes Taiwan as part of China -- and Chinese officials were furious over the first conversation in decades between a Taiwanese leader and a US President or President-elect.