President-elect Donald Trump’s surrogates on Sunday defended his controversial phone call with Taiwan President Tsai Ing-wen, which critics say threatens to cause a rift with China and upend decades-long diplomatic protocol.

Trump and his advisers have said the call was initiated by the Taiwanese government, and that the conversation does not signal a change in the U.S.’s “one-China” policy in which the U.S. government does not formally recognize that of Taiwan—a policy that originated in 1979 when President Jimmy Carter officially declared Beijing as the governing body of China.

Indiana Gov. Mike Pence, the vice president-elect, said it was merely a “courtesy call” among dozens of other calls made and received by Trump since the election.

“There is a great sense of enthusiasm and optimism” among world leaders, Pence insisted Sunday on NBC’s “Meet the Press,” and the calls are “a reflection of the tremendous energy” that is behind Trump's election and foreign policy, which he described as having “broad shoulders.”

The Chinese government views Taiwan simply as a rogue state, and has insisted on a “one-China” policy as part of its diplomatic dealings with other nations. The vast majority of nations choose to recognize Beijing as the sole government of China. Trump’s decision to take a call from Taiwan’s leader suggests a new foreign policy approach in which the president overlooks long-term norms in favor of a policy on the fly.

Kellyanne Conway, a senior adviser to the Trump transition team, downplayed the significance and potential ramifications of the conversation between the two leaders.

“It was just a phone call at this point. It signals the fact that he accepted a congratulatory call,” Conway said on “Fox News Sunday,” acknowledging that the U.S., China and Taiwan all have different points of view with respect to the call.

“When he is sworn in as president and commander-in-chief in a little over a month, Chris, he will make clear what the fullness of his plans are, but people shouldn’t read too much into it.”

Conway said Trump is “routinely briefed” on foreign affairs, and that they were always aware of the “one-China” policy.

Officials at the State Department have indicated that neither Trump nor a member of his transition team has consulted with the department in advance of the president-elect’s phone calls with world leaders.

China’s foreign minister, Wang Yi, called the conversation a “small trick,” and said it was unlikely to affect U.S. policy. The Chinese Foreign Ministry later issued a formal complaint with the U.S. over the phone call, calling Taiwan “inseparable” from Chinese territory.

“We urge the relevant side in the U.S. to adhere to the ‘one-China’ policy, abide by the pledges in the three joint China-U.S. communiques, and handle issues related to Taiwan carefully and properly to avoid causing unnecessary interference to the overall China-U.S. relationship,” foreign ministry spokesman Geng Shuang said.

Others, like former top White House aide Dan Pfeiffer, said simply: Trump “got played like a fool.”

According to Trump’s staff, Trump and Tsai discussed “the close economic, political, and security ties exists [sic] between Taiwan and the United States.”

A report last month suggested that Trump was looking to expand his business interests in Taiwan, fueling more claims of a conflict of interest between his soon-to-be role as president and his decision-making power as chief executive of the Trump Organization.