The United States will defend Taiwan if it is attacked by China, President Joe Biden said, seemingly changing long-standing American “strategic ambiguity” on the issue.

“Yes,” Biden said at a Town Hall hosted by CNN when asked by the anchor, Anderson Cooper, if the US will come to Taiwan’s defence if attacked by China. “Yes, we have a commitment to do that,” the US president said further when the anchor pressed him, on Thursday.

Joe Biden’s remarks came just a day after his pick for ambassador to China, Nicholas Burns, told US senators at his confirmation hearing that “strategic autonomy” in relation to Taiwan is working and there is no need to change it.

The United States recognises China’s claims over Taiwan under its One-China Policy, but under the Taiwan Relations Act, it is committed to helping the island nation defend itself against China. The United States provides Taiwan with massive amounts of military hardware to that end.

But the US has kept its commitment to coming to Taiwan’s defence in the event of its invasion by China vague, which is defined as “strategic ambiguity”.

President Joe Biden seemingly changed that.

The White House sought to walk back his comments. “The president was not announcing any change in our policy, and there is no change in our policy,” a White House spokesperson said after the Town Hall. “The US defence relationship with Taiwan is guided by the Taiwan Relations Act. We will uphold our commitment under the act, we will continue to support Taiwan’s self-defence, and we will continue to oppose any unilateral changes to the status quo.”

That indeed remains the policy of the Joe Biden administration as stated by Nicholas Burns at the hearing. “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,” he said in response to a senator’s remarks that Beijing takes strategic ambiguity as a sign of weakness. “This is a policy that can succeed if we execute it consistently and with some strength.”

He further said: “We recognise the People’s Republic of China as the sole legal government of China. And, yet we have unofficial relations with Taiwan, and we have under the Taiwan Relations Act the ability, in fact, the imperative, of helping Taiwan to defend itself. Every president, Republican and Democrat, has followed that policy.”

The United States has been closely watching recent escalation in tensions between China and Taiwan. Beijing sent a “record number” of warplanes close to Taiwan earlier this month forcing a top Taiwanese defence official say that tensions were at their worst in 40 years.