WASHINGTON (AFP) - United States Secretary of State Antony Blinken will deliver a long-awaited speech on China on Thursday (May 26), the State Department said, days after President Joe Biden made waves by promising to defend Taiwan.

Mr Blinken had been due to deliver the speech earlier this month, ahead of Mr Biden's trip to Japan and South Korea, but postponed it after testing positive for Covid-19.

Aides have billed the speech, to take place at George Washington University with the Asia Society as host, as the most comprehensive statement to date on the administration's policy towards the rising Asian power.

Mr Biden, at a news conference in Japan, appeared to break with decades of reticence by saying that the US would defend Taiwan militarily if attacked by China, which claims the self-governing democracy as its territory.

But Mr Biden later said there was no change in the US policy of "strategic ambiguity" - in which the US promises to provide Taiwan with the means to defend itself but stops short of promising to intervene directly.

The Biden administration took office characterising China as a top priority and describing it as the only global long-term competitor for the US.

The administration, however, has toned down some of the harsh rhetoric of former president Donald Trump and voiced a willingness to cooperate with Beijing in limited areas such as climate change.

Mr Blinken's speech is part of a renewed effort by the Biden administration to demonstrate its focus on Asia after months of efforts supporting Ukraine after it was invaded by Russia.

Mr Biden earlier in May also welcomed South-east Asian leaders for a first-of-a-kind summit in Washington.