The Obama administration says the United States should not use its "One China" policy as a "bargaining chip" with China.
White House spokesman Josh Earnest Monday was reacting to President-elect Donald Trump's statement Sunday that he does not know why the U.S. should be bound by that policy unless a deal on other matters, such as trade, is made.
Since 1979, the U.S. has recognized China's official position that Taiwan is part of China.
"That's also the policy, by the way, that previous presidents in both parties had pursued and our country has benefited from adherence to that policy," Earnest said. "This is an issue that the Chinese government considers to be highly sensitive, and disrupting this policy could have a disruptive effect on our ability to work with China where our interests align."
Earnest mentioned Chinese cooperation on climate change, the nuclear agreement with Iran and the pressure China puts on North Korea as examples in which "common ground" benefits Americans, the Chinese, and the the entire planet.
Earnest said that such progress would be "much more difficult if tensions are heightened around our One China policy."
Trump told Fox News Sunday he does not want China telling him what to do.
"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...you have North Korea. You have nuclear weapons, and China could solve that problem, and they're not helping us at all," Trump said.
A Chinese foreign ministry spokesman Monday said the one-China policy is the foundation of U.S.-China relations and urged Trump to "understand the seriousness."
The state-controlled Global Times suggested if Trump supports Taiwan independence or weapons sales, then China "would have no grounds to partner with Washington on international affairs," and could offer military and other support to U.S. opponents.
Trump also defended his controversial and unprecedented telephone call with Taiwanese President Tsai Ing-wen, congratulating him on winning last month's election.
Trump said it would have been disrespectful not to talk to her.
"It was a very nice call, short," Trump said. "And why should some other nation be able to say I can't take a call?"
Chinese nationalists fled to Taiwan in 1949 after the Communist takeover of the mainland. The nationalists set up a separate government on the island, but China has always regarded Taiwan as part of the central government.
The U.S. and Taiwan are robust trading partners and the U.S. is committed to come to Taiwan's aid if China tries to use military force to put down a formal declaration of independence by Taiwan.
VOA State Department correspondent Nike Ching contributed to this story.