US President-elect Donald Trump threw into doubt four decades of US foreign policy towards China by saying Washington is not bound to maintain its long-standing position that Taiwan is part of "one China."

Trump's comments on "Fox News Sunday" came after he sparked a diplomatic protest from Beijing over his decision to accept a congratulatory telephone call from Taiwan's president earlier this month.

"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 during the TV broadcast.

Trump's call with President Tsai Ing-wen was the first such contact with Taiwan by a US president-elect or president since President Jimmy Carter shifted diplomatic recognition from Taiwan to China in 1979, viewing Taiwan as part of "one China."

Taiwan's status is a sensitive issue for China, which considers the island a renegade province.

Chinese officials did not immediately respond to Trump's remarks, but within hours an unsigned commentary on a nationalist website slammed the president-elect, calling Trump "as ignorant of diplomacy as a child."

The commentary in Global Times said, "The one-China policy cannot be traded."

After Trump's phone conversation with Taiwan's president, the Obama administration said senior White House aides had reassured Chinese officials that Washington's "one-China" policy remained intact.

The administration also warned that progress made in the US relationship with China could be undermined by a "flaring up" of the Taiwan issue.

The South China Sea

The White House did not respond to Trump's latest comments beyond referring to its previously stated policy positions.

During Sunday's TV interview Trump criticized China over its currency policies, its activities in the South China Sea and its stance toward North Korea. He added that it was not for 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 in to me," 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," Trump added.

During the TV interview Trump echoed a host of complaints about China, which he first raised during his presidential campaign.

"We're being hurt very badly by China with devaluation, with taxing us heavy at the borders when we don't tax them, with building a massive fortress in the middle of the South China Sea, which they shouldn't be doing, and frankly with not helping us at all with North Korea," Trump said.

"You have North Korea," he continued. "You have nuclear weapons and China could solve that problem and they're not helping us at all."

The Global Times commentary warned that if Trump openly supported Taiwan's independence, or increased arms sales to the island, China could retaliate by aiding "forces hostile to the US." 

bik/kl (Reuters, AFP, dpa)