Jane Onyanga-Omara

USA TODAY

China said Monday it has “serious concern” about comments by Donald Trump regarding the self-governing island of Taiwan. The country's reaction came a day after the president-elect said he did not feel “bound by a one-China policy” in a television interview.

China also warned that any changes to the United States' dealings with Taiwan could damage diplomatic relations between Beijing and Washington. The U.S. sees Taiwan as part of "one-China" and maintains a formal relationship with China and an unofficial one with the island.

In an interview broadcast on Fox News on Sunday, Trump said: "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."

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Geng Shuang, a spokesman for China’s foreign ministry, said Monday that established policy is the “political foundation” of any diplomatic relationship between China and the U.S., and that any damage to it could make cooperation between both sides “out of the question,” the Associated Press reported.

“We urge the new U.S. leader and government to fully understand the seriousness of the Taiwan issue, and to continue to stick to the one-China policy,” Geng said, according to the AP.

The Global Times, a state-run Chinese newspaper, said in an editorial Monday that Trump was “as ignorant as a child."

Taiwan: Trump call was not China 'policy shift'

Last week, Taiwan’s leader Tsai Ing-wen told USA TODAY that a 10-minute phone call between her and Trump on Dec. 2 did not signal a change in policy and was "a way for us to express our respect for the U.S. election.”

Trump said the call was “very nice” and was to congratulate him on winning the presidential election.

“Why should some other nation be able to say I can’t take a call?” he said. “I think it actually would’ve been very disrespectful, to be honest with you, not taking it," he told Fox.

The phone call overturned decades of diplomatic protocol and was the first known contact between a U.S. president or president-elect and a Taiwanese leader since the U.S. ended formal relations with the island in 1979. The call riled China, which considers Taiwan a province and not an independent country.

Contributing: Donna Leinwand Leger