US President Donald Trump and House Speaker Nancy Pelosi traded insults on Thursday, each questioning the other’s mental stability.
The top Democrat called on Mr Trump’s family and aides to conduct an intervention with the president “for the good of the country”.
Mr Trump hit back, saying Mrs Pelosi was “crazy”, later calling the California congresswoman “a mess”.
The row marks a new low for relations between the White House and Democrats.
The exchange came a day after Mr Trump abruptly cut short a meeting with Mrs Pelosi and her counterpart in the Senate, Democratic leader Chuck Schumer.
The fallout from the meeting – which the president ended in minutes – continued throughout the following day.
In a response to a question at her weekly press briefing on Thursday, Mrs Pelosi said she was concerned for the well-being of the president “and the well-being of the United States of America”.
The speaker accused Mr Trump of a “temper tantrum”.