"Our policy has not changed," Austin told reporters, after being asked about the meaning of Biden's comments.

Speaking in Japan earlier Monday, Biden answered "yes" when asked if Washington was willing to get involved militarily to defend Taiwan.

"That's the commitment we made," he added.

"We agreed with the One China policy, we signed on to it... but the idea that it can be taken by force is just not appropriate, it would dislocate the entire region and would be another action similar to Ukraine," Biden said.

China views the self-ruled democratic island of Taiwan as part of its territory to be re-taken one day, and tensions in the region have risen in recent months.

Biden's remarks, the second time in his presidency that he appeared to pledge the US military would protect Taiwan, moved sharply from the longstanding, deliberately ambiguous position that Washington has maintained on Taiwan to avoid angering Beijing.

But Austin insisted that the policy of the past decades remained in place.

"As the president said, our One China policy has not changed. He reiterated that policy and our commitment to peace and stability across the Taiwan Strait," Austin said.

"He also highlighted our commitment under the Taiwan Relations Act, to help provide Taiwan the means to defend itself. So again, our policy has not changed," he said.