The ghostwriter who penned Donald Trump's 1987 memoir The Art of the Deal thinks the US president will resign before the end of his term.
Tony Schwartz tweeted that "Trump is going to resign" before investigators probing alleged ties between the Republican's campaign team and Russia "leave him no choice".
"The circle is closing at blinding speed," the author tweeted.
"Trump is going to resign and declare victory before Mueller and congress leave him no choice."
"Trump's presidency is effectively over," he said in a follow-up tweet. "Would be amazed if he survives till end of the year. More likely resigns by fall, if not sooner."
While writing Mr Trump's bestselling breakthrough memoir Mr Schwartz spent 18 months with the billionaire tycoon.
He spoke out last year against the real estate mogul during the presidential campaign, telling The New Yorker magazine that he put "lipstick on a pig".
"I feel a deep sense of remorse that I contributed to presenting Trump in a way that brought him wider attention and made him more appealing than he is."
16 members of POTUS Arts & Humanities Cttee resign- "Your words & actions push us all further away from the freedoms we are guaranteed" https://t.co/0FGGjaVayU
— Caitriona Perry (@CaitrionaPerry) August 18, 2017
Mr Trump has alienated Republicans, corporate leaders and US allies, rattled markets and prompted speculation about possible White House resignations with his comments since Saturday's violence in Charlottesville, Virginia, during a white nationalist protest against the removal of a Confederate statue.
Republican Senator Bob Corker, chairman of the Senate Foreign Relations Committee, questioned Mr Trump's capacity to govern.
"The president has not yet been able to demonstrate the ability or the competence that he needs to be successful," said Mr Corker, who Mr Trump had considered for the job of secretary of state.
He said Mr Trump needed to make "radical changes."
Last night in response to the Barcelona terror attack, Mr Trump appeared to endorse the idea of mass executions for Islamist extremists, as he alluded to a widely debunked account of summary punishment by a US general in the Philippines in the early 1900s.
The tweet also suggested Trump actually believes a story that many historians say is apocryphal.
He first sent out a tweet offering aid to Spain.
The United States condemns the terror attack in Barcelona, Spain, and will do whatever is necessary to help. Be tough & strong, we love you!
— Donald J. Trump (@realDonaldTrump) August 17, 2017
About an hour later, Mr Trump tweeted: "Study what General Pershing of the United States did to terrorists when caught. There was no more Radical Islamic Terror for 35 years!"
He was referring to General John "Black Jack" Pershing who was the US governor of largely Muslim Moro province from 1909 to 1913.
Study what General Pershing of the United States did to terrorists when caught. There was no more Radical Islamic Terror for 35 years!
— Donald J. Trump (@realDonaldTrump) August 17, 2017
At the time, the Philippines was a US colony and Pershing's forces had to fight Muslim counterinsurgencies.
The debunked account - which Trump has referred to in the past - is that Pershing's forces rounded up 50 Muslim insurgents and executed 49 of them with bullets dipped in pig's blood - considered by Muslims to be unholy.
"You heard that, right?" Trump said as a candidate during a rally in February 2016 in South Carolina, alluding to the pig blood part.
"They were having terrorism problems, just like we do," Mr Trump said.
As the story goes, the 50th prisoner was released to tell his fellow fighters about what the Americans had done.
"And for 25 years, there wasn't a problem. Okay? Twenty-five years, there wasn't a problem," Mr Trump said.
Historians have expressed scepticism or outright denial that this event took place.
According to the fact checking website Politifact, the late military historian Frank Vandiver said in 2003, referring to Pershing: "I never found any indication that it was true in extensive research on his Moro experiences. This kind of thing would have run completely against his character."
Politifact quoted four historians who denied the account.
