President Joe Biden is seeking to show U.S. resolve against China, yet an ill-timed gaffe on Taiwan risks undermining his bid to curb Beijing’s growing influence over the region.

Whether intentional or not, Biden provoked China with a vow to defend Taiwan militarily. After saying that U.S. policy on Taiwan “had not changed at all” during a news conference in Tokyo, he then answered “yes” when asked if the U.S. would act “militarily” to defend the island in the event of a Chinese attack.

“It’s a commitment we made,” Biden added.

White House officials later walked back the remark, saying the president was only promising U.S. aid to help Taiwan defend itself in the event of hostilities. That would be akin to what the U.S. is doing in Ukraine, where Biden has vowed not to send troops.

“The policy has not changed at all, and I stated that when I made my statement,” Biden said Tuesday when pressed by reporters to clarify the U.S. position.

The president’s remark nonetheless roiled Biden’s first trip to Asia since taking office and upstaged his roll-out of a new strategic framework for the region. It also cast new light on Washington’s decades-old approach of “strategic ambiguity” about whether U.S. forces would defend Taiwan against China, while also adopting a “One China” policy under which Taiwan isn’t recognized as an independent country.

It’s a complicated policy, criticized both by Beijing and some U.S. lawmakers, that has tripped up Biden and some of his predecessors in the past. Biden has made similar missteps on Taiwan at least twice as president, but in making the remark so close to Chinese territory and in the context of the Ukraine war, the impact was amplified.

Although the latest episode is unlikely to fundamentally alter the U.S.-China relationship, it highlights the current tension around Taiwan at a time when Chinese officials have expressed concern about American efforts to box in their country. And Biden’s remark also opened him to criticism by domestic political opponents who have sought to portray the president, 79, as infirm and unfit for the job.

Sen. Tom Cotton, an Arkansas Republican, said that Biden’s comments represented a shift toward “strategic clarity” on Taiwan and that the president should outline a clear U.S. commitment to defend the island “in clear, deliberate remarks from a prepared text.”

“Otherwise, the continued ambiguity and uncertainty will likely provoke the Chinese communists without deterring them - the worst of both worlds,” he said.

Indeed, one Chinese official suggested that Biden’s comment may have been deliberate, aimed at testing Beijing’s response to a policy change. The official, who asked not to be identified describing internal Chinese government discussions, portrayed such a potential U.S. approach as dangerous.

China’s leaders have closely watched the Ukraine crisis unfold, taking note of Russia’s political and economic isolation as well as the massive international support for Kyiv as they consider their posture toward Taiwan.

And Biden spoke in Tokyo, the capital of a major Chinese rival, on a trip to strengthen the U.S. alliance with new, Washington-friendly leaders of Japan and South Korea, two countries already unfriendly toward Beijing.

Biden’s previous comments about U.S. support for Taiwan happened during domestic television interviews.

“The level of concern in Beijing about U.S. policy toward Taiwan is already very high, and this episode will further heighten that concern, especially since it was said in Tokyo,” said Bonnie Glaser, Asia program director at the German Marshall Fund of the U.S..

While Biden’s intent may have been to deter a Chinese attack on Taiwan, “his messaging is confusing and may undermine deterrence,” Glaser added. The U.S.’s policy of “strategic ambiguity” on Taiwan, which Biden has repeatedly backed during his five-decade Washington career, is intended to minimize the risk of a direct military confrontation with China.

White House officials said after Biden’s news conference that the president stands behind the “One China” policy and its commitment under the Taiwan Relations Act to provide the island with the military means to defend itself. Officials said that by answering “yes” when asked if the U.S. would defend Taiwan, the president meant the U.S. would supply military equipment to the island, not send troops.

Chinese Foreign Ministry spokesman Wang Wenbin nonetheless denounced Biden’s comments on Monday and said the U.S. should refrain from sending the wrong message on Taiwan, “to avoid causing grave damage to bilateral relations.”

Although Biden may have sought to evoke a Ukraine-like effort to keep Taipei supplied in the event of an invasion, the island would present an entirely different strategic challenge. It doesn’t share a land border with American allies, as does Ukraine, meaning China could more easily blockade its ports and airports to prevent resupply.

Biden’s comments set off a now-familiar cycle for White House aides, who have become accustomed to cleaning up the president’s remarks on world hot spots. After Biden declared in Poland that Russian President Vladimir Putin “cannot remain in power,” his advisers insisted the president wasn’t advocating regime change.

And Biden told reporters that lawyers at the State Department might feel differently after he labeled Russia’s invasion of Ukraine a “genocide.”

Biden previously said the U.S. would come to Taiwan’s defense during an ABC News interview in August and in a CNN town hall in October. The U.S. abandoned its post-Chinese civil war position that it would defend Taiwan in the late 1970s when it normalized relations with Beijing.

Biden, who as a senator chaired the Foreign Relations Committee for about four years, has on other occasions used language that appeared to alter U.S. policy on Taiwan, including by describing the island last year as “independent.”

Several of Biden’s predecessors had similar trouble with Taiwan.

President Donald Trump made a congratulatory phone call to Taiwan’s president, Tsai Ing-wen, in December 2016 after her election -- the first time a U.S. president or president-elect had spoken directly to Taiwan’s leader since 1979. And Trump publicly mused before taking office about abandoning the “One China” policy, only to restate the U.S. position in February 2017.

President George W. Bush agreed with an ABC News interviewer that the U.S. had an obligation to defend Taiwan in the event of a Chinese attack and said that the U.S. would provide “whatever it took to help Taiwan defend herself.”

No matter the clean-up by White House officials, China has always assumed U.S. involvement in any conflict with Taiwan, said Ryan Hass, the Cecilia Yen Koo Chair in Taiwan Studies at the Brookings Institution.

“Beijing always has had to base its military plans in the Taiwan Strait on an assumption of U.S. military intervention, Hass said. “It would represent strategic malpractice for Beijing to assume anything otherwise.”

The Chinese Embassy in Washington declined to elaborate on the foreign ministry’s comments. The White House didn’t respond to a request for additional comments.

“The U.S. will suffer the consequences and the American people may rebel if the U.S. president wants to send American soldiers to fight in Taiwan,” said former Chinese diplomat Gao Zhikai.

U.S. National Security Adviser Jake Sullivan said last week that Biden may speak with Chinese President Xi Jinping in coming weeks, and Xi may decide to wait until that conversation before reaching judgments about the U.S. policy direction toward Taiwan, Hass said.

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Bloomberg’s Jennifer Jacobs, Nancy Cook and Philip Glamann contributed to this report.