Trump is expected to meet in the coming week with Chinese President Xi Jinping during a summit in South Korea, with Trump eyeing a deal on trade relations between the world's two largest economies.

"Taiwan has a lot of things that they're worried about and rightfully so because of the situation they find themselves in," Rubio told reporters on his plane between Israel and Qatar.

"If what people are worried about is we're going to get some trade deal or we're going to get favourable treatment on trade in exchange for walking away from Taiwan, no one is contemplating that," he said.

Under longstanding policy, the United States recognises only Beijing but provides weapons for the self-defence of Taiwan, a self-governing democracy claimed by China.

Trump during his campaign sent mixed signals on his commitment to Taiwan, and at times has cast the high-tech powerhouse as an economic competitor.

Trump recently said that he doubted China was planning to invade Taiwan, pointing in part to what he called his good relationship with Xi.