Apotential visit to Taiwan by US House Speaker Nancy Pelosi is stirring alarm in President Joe Biden's administration which fears the trip may cross red lines for China -- and that there is no exit path.

China on Monday warned it was "getting ready" for a Pelosi visit to the self-ruling island next month and that the United States would "bear all responsibility for all serious consequences" if she goes.

Biden was open last week about concerns, saying the US military opposed travel by Pelosi, a fellow Democrat who is second in line to the presidency after the vice president.

Congress is constitutionally an equal branch of government with lawmakers free to travel where they wish. But the administration worries the nuance is lost on Beijing, which sees rising American support for Taiwan as part of a plot to push declared independence for the territory it claims.

The trip could come at an especially fraught time as President Xi Jinping, China's most powerful leader in decades, prepares to cement his rule later this year at a major party meeting amid economic headwinds.