Last Sunday, Trump himself said in an interview on Fox News Sunday: "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."
Political analysts said that Republican Trump's call with the president of Taiwan and the comments on the "one China" policy could antagonize Beijing.
Trump also inserted himself on Saturday into another sensitive dispute between China and the United States after China on Thursday seized an underwater drone owned by the U.S. military in the South China Sea. Trump called the seizure an "unprecedented act."
U.S. officials described the seizure as the first of its kind in recent memory. It was taken about 50 nautical miles northwest of Subic Bay off the Philippines just as the USNS Bowditch was about to retrieve it, the officials said.
Although China vowed to return the drone to the United States, Trump later tweeted that the U.S. should let China keep it.
Priebus on Sunday defended the comments on the drone, saying he does not believe Trump's comments were provocative and that "80 percent" of Americans agree it was inappropriate for China to have seized the drone in the first place.
Republican Senator John McCain, chairman of the Senate Armed Services Committee, told CNN's "State of the Union" that the Chinese would be able to retrieve some "pretty valuable" technical information from the drone through a process known as reverse-engineering.
McCain said the Chinese seizure of the drone was a "gross violation" of international law. McCain, a critic of Democratic President Barack Obama's foreign policy, said the United States was not projecting enough strength in the world and said China's move reflected that.
"Everybody is taking advantage of it, and hopefully that will change soon," McCain said.