President Joe Biden said on Sunday that the United States would militarily defend Taiwan if China attacked, reiterating his support for the island as Beijing expressed its displeasure.

Biden was asked on “60 Minutes” if “US forces” would respond to aid Taiwan against China. “If there was an unprecedented attack,” he said.

“So, unlike Ukraine, sir, U.S. forces — U.S. men and women — would defend Taiwan in the event of a Chinese invasion?” he was asked again.

“Yes,” Biden replied.

His response is similar to his response when a reporter asked him a similar question during a press conference in Tokyo in May, and it’s at least the fourth time he’s said something along these lines, appearing to go beyond the historic US policy of “strategic ambiguity” about Taiwan’s relationship with China, which views the island as a breakaway province despite Taiwan’s separate government.

The US is legally required to provide Taiwan with resources to defend itself, but an American military response if China invades is not required.

Since the 1970s, and as codified by the 1979 Taiwan Relations Act, the United States has recognized the People’s Republic of China as China’s sole legal government, while officially considering Taiwan’s status as unresolved and maintaining unofficial ties with the island, which emerged as a separate faction following the Chinese civil war.

Chinese government spokesperson Mao Ning said at a press conference in Beijing on Monday that China had filed complaints with the US in response to Biden’s remarks about Taiwan.

She stated that China “deplores” and “strongly opposes” the president’s recent statements and that the country reserves the right to take all necessary measures, but that it is “willing to do our best to strive for peaceful reunification.”

After Russia’s invasion of Ukraine earlier this year, Biden said the “burden” of the US “commitment” to defend Taiwan was “even stronger.”

Taiwanese Foreign Ministry spokesperson Joanne Ou stated at the time that their government “sincerely welcomes and thanks President Biden and the United States government for reiterating its rock solid commitment to Taiwan.”

At the time, a White House official told ABC News that Biden’s remarks did not represent a shift because the president “reiterated our commitment… to provide Taiwan with the military means to defend itself.”

“The president has said this before, including earlier this year in Tokyo,” an official said. “He also stated at the time that our Taiwan policy had not changed.” That is still true.”

When a reporter in Tokyo asked Biden how the United States would respond if China invaded or attempted to take over Taiwan, the president first stated, “Our policy toward Taiwan has not — Taiwan — has not changed at all.”

However, the reporter followed up by asking, “Are you willing to get involved militarily to defend Taiwan if necessary?” “Yes,” Biden replied. When asked, “Are you?” he replied, “That’s the commitment we made.”

When asked the next day if the policy of ambiguity toward Taiwan was “dead,” Biden replied, “No.”

“The policy has remained unchanged. When I made my statement yesterday, I stated, “He stated.

A White House official said in July, after Biden and China’s leader Xi Jinping spoke, that their discussion on Taiwan was “direct” and “honest,” with Biden reaffirming the US commitment to its historic position. However, the official refused to respond to a Chinese readout claiming Xi said, “Playing with fire will set you on fire.”

“President Xi used similar language in the conversation that the two leaders had back in November,” the administration official said. “But you know, I’m not going to get into parsing the various metaphors that the PRC regularly tends to use on these issues.”