A spokesman for China’s foreign ministry said Saturday that Beijing lodged an official complaint with the United States. Asked about the incident, China’s foreign minister, Wang Yi, called the call a “petty” move by Tsai. “The One China principle is the foundation for heathy development of Sino-U.S. relations. We don’t wish for anything to obstruct or ruin this foundation,” Wang said.

But experts predicted surprise and anger as Beijing takes stock over the weekend. “This is a heavy blow,” said Zhu Feng, dean of the School of International Relations at Nanjing University…

Paul Haenle, who was on the National Security Council staffs of former president George W. Bush and President Obama and is now director of the Carnegie-Tsinghua Center in Beijing, said the incident showed the importance of Trump taking daily intelligence briefings, consulting with experts at the State Department and Department of Defense and quickly assembling a China team.

When it comes to China, past administrations took a “no surprises” approach, Haenle said. “The alternative — catching China by surprise on some of the most sensitive and longstanding areas of disagreement in our relationship — presents enormous risks and potential detriment for this consequential relationship.”