Donald Trump pulled the plug on infrastructure talks with Democrats in spectacular fashion on Wednesday, storming out a meeting over their refusal to drop "phony investigations" into his administration.
In what political opponents described as jaw-dropping behaviour, the US president reportedly refused to shake hands at the White House talks, instead delivering a five-minute rebuke.
Mr Trump told the gathering of senior Democratic congressmen that he would not negotiate on new legislation, such as an infrastructure spending bill, unless their inquiries into his presidency were dropped.
The US president is said to have the left without waiting for a response, walking into a press conference in the White House's Rose Garden which was unexpectedly called to accentuate his message.
Mr Trump said that Democrats could not go down "two tracks" at the same time, adding: "You can go down the investigation track or you can go down the investment track."
He pinpointed a comment by Nancy Pelosi, the Democratic leader of the House of Representatives, who earlier in the day had accused Mr Trump of overseeing a "cover-up", as a trigger for his move.
However Democrats pushed back, insisting they had come to the White House in good faith - attendees included senior congressmen who control relevant committees - in their own press conference after talks collapsed.
Ms Pelosi accused Mr Trump of "taking a pass" on infrastructure, saying: "For some reason, maybe it was lack of confidence on his part, he really couldn't match the greatness of the challenge that we had."
Chuck Schumer, the most senior Democrat in the Senate who also attended the meeting, said: "To watch what happened in the White House would make your jaw drop."
He said Mr Trump's actions were not "spontaneous" but "planned", noting that the room's curtains had been drawn and an area left clear for Mr Trump to deliver his rebuke.
He also noted that a poster listing facts about the scale of Robert Mueller's Russia investigation which was pinned to Mr Trump's podium during his press conference must have been printed in advance.
The row has been brewing for weeks, with the Democrats using their majority in the House to launch a string of investigations into Mr Trump's administration, including topics covered in the Mueller report.
Mr Trump has repeatedly criticsed the investigations and attempted to slow their progress, stopping witnesses from appearing and blocking the release of documents - prompting Ms Pelosi's "cover-up" comment.
Mr Trump and leading Democrats had gathered last month in a meeting on infrastructure which was lauded by both sides as positive. But with talks now broken down there is little chance of progress in the near future.
Ms Pelosi later said that Mr Trump's behaviour, including the rejection of subpoenas issued by Democrat-controlled congressional committees, could amount to an "impeachable offense".
She said: "The fact is, in plain sight, in the public domain, this president is obstructing justice and he's engaged in a cover-up. And that could be an impeachable offense."