US cleans up Biden's 'commitment' to defend Taiwan from Chinese invasion

The Biden administration is again playing cleanup after President Joe Biden said the U.S. would come to Taiwan's defense in the event of an invasion by mainland China -- despite decades of policy that leaves that an open question.

His comment prompted a stern warning from the People's Republic of China, which considers the self-governing island a breakaway province, especially since Biden has made it twice now in the last couple of months.

That's led to speculation that Biden may be pushing the boundaries of "strategic ambiguity," the longstanding U.S. policy that leaves unanswered whether and how the U.S. would intervene in a conflict across the Taiwan Strait. In recent months, as China has escalated its incursions into Taiwan's air defense zone and ramped up its rhetoric about reunion, some China hawks in Washington have called for an end to the policy.

But the White House, the State Department, and the Pentagon all said Friday there was no change in U.S. policy despite Biden's answer during a CNN town hall.

"There has been no shift," White House press secretary Jen Psaki told reporters. "The president was not announcing any change in our policy, nor has he made a decision to change our policy. There is no change in our policy."

Speaking at NATO headquarters, Defense Secretary Lloyd Austin said the U.S. would continue to provide Taiwan "the sorts of capabilities that it needs to defend itself." But he dismissed questions about a Chinese attack as a "hypothetical."

State Department spokesperson Ned Price went the further, telling reporters, "We have been nothing but clear when it comes to where we stand."

But Biden has been anything but clear. In August, the president told ABC News's George Stephanopoulos that the U.S. had a commitment to act "if in fact anyone were to invade or take action against NATO," Japan, South Korea and Taiwan. While that's true of the first three -- all treaty allies of the United States -- it isn't of Taiwan.

Instead, since a 1979 agreement, the U.S. has acknowledged the People's Republic of China as the sole legal government of China, including its position that Taiwan is part of China -- what's known as the "One China" policy. But under that agreement, the U.S. has maintained unofficial relations with Taiwan's government, which is defined by a 1979 law that then-senator Biden voted for. The law commits the U.S. "to assist Taiwan in maintaining its defensive capability," to oppose any one-sided changes in the status quo and to support a peaceful resolution to their differences, according to the State Department.

But Biden contradicted that again on Thursday, telling CNN's Anderson Cooper that he would have the U.S. military come to Taiwan's defense.

"If China attacked?" Cooper followed up -- and Biden responded, "Yes, we have a commitment to do that."

In response, China's Foreign Ministry issued its own warning about its "determination and ability to defend national sovereignty and territorial integrity."

"We urge the U.S. to strictly abide by the one-China principle and the three Sino-U.S. joint communiqués, be cautious in its words and deeds on the Taiwan issue, and refrain from sending any false signals to the 'Taiwan independence' separatist forces -- or it will seriously damage to Sino-U.S. relations and peace and stability across the Taiwan Strait," said Wang Wenbin during a briefing Friday.

Some China hawks in the U.S. have been urging the administration to end "strategic ambiguity" and clearly commit to Taiwan's defense, arguing China's increasing pressure on the island is a signal it is preparing to retake it by force and that a clear U.S. commitment would deter that.

But Biden's own pick for U.S. ambassador to China disagreed, just one day prior to the president's comments. During his Senate confirmation hearing Wednesday, retired career ambassador Nick Burns called for strengthening the U.S. military position in the region and selling weapons to Taiwan to make it a "tough nut to crack."

When asked about ending "strategic ambiguity," however, Burns said, "My own view, and this is also the view ... more importantly of the Biden administration, is that the smartest and effective way for us to help deter aggressive actions by [China] across the Taiwan Strait will be to stay with a policy that's been in place."

It's not the first time an American president has had to walk back comments about Taiwan's defense. In 2001, shortly after he took office, George W. Bush told ABC News's Charlie Gibson he would also come to Taiwan's defense.

"With the full force of the American military?" asked Gibson. Bush responded: "Whatever it took to help Taiwan defend herself."

Biden, then the chairman of the Senate Foreign Relations Committee, blasted Bush in an editorial, writing, "In this case, his inattention to detail has damaged U.S. credibility with our allies and sown confusion throughout the Pacific Rim."

"Words matter, in diplomacy and in law," Biden added.

ABC News's Karson Yiu contributed to this report from Hong Kong and Ben Gittleson from the White House.