President-elect Donald Trump has questioned whether the US should continue its “One China” policy.
US policy since 1979 has respected China’s stance on Taiwan, which it sees as a breakaway province.
But Mr Trump said that without concessions from Beijing on trade and other issues, he did not see why that should continue.
Relations with China became strained when Mr Trump took a phone call from Taiwanese President Tsai Ing-wen.
Mr Trump went on to post a series of tweets criticising China for its exchange rate policy and its operations in the South China Sea.
Speaking in an interview with Fox News broadcast on Sunday, Mr Trump said: “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.”
Mr Trump also said China was not co-operating with the US on its handling of its currency, on North Korea, or on tensions in the South China Sea.
In the same interview, Mr Trump said he “doesn’t believe” a CIA assessment that Russian hackers tried to sway the US presidential election in his favour.
‘Very disrespectful’
Mr Trump’s decision to take a phone call from the Taiwanese president earlier this month was a break with US diplomatic tradition and prompted a formal protest from Beijing.
No US president or president-elect had spoken directly to a Taiwanese leader for decades.
But in the Fox interview, Mr Trump said it was not up to Beijing to decide whether he should take a call from Taiwan’s leader.
“I don’t want China dictating to me and this was a call put into me,” Mr Trump said. “It was a very nice call. Short. And why should some other nation be able to say I can’t take a call?
“I think it actually would’ve been very disrespectful, to be honest with you, not taking it.”
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For China, it is difficult to think of a more important issue in its relations with other countries than the One China policy.
Beijing considers Taiwan part of its own territory – and insists that all its diplomatic partners publicly share this view.
Former US President Jimmy Carter had to cut official ties with Taiwan before he could open an embassy in Beijing in 1979.
The policy has been the bedrock of Sino-American relations ever since.
Mr Trump suggested the One China agreement could be used as a kind of bargaining chip in negotiations on other issues, such as trade. But it is hard to image the circumstances in which that might be acceptable in Beijing.
China recently played down a telephone call between Mr Trump and Taiwan’s President Tsai Ing-wen.
But it will become increasingly alarmed if the US president-elect continues to suggest American policy towards China is about to change.
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