Donald Trump testifies: Ex-president clashes with judge at New York fraud trial
The judge at Donald Trump's New York civil fraud trial has admonished him to "answer the questions, no speeches" as he began testimony in a case that could dismantle his business empire.
Judge Arthur Engoron gave the warning to Mr Trump, 77, soon after he took the stand in the Manhattan court.
As he arrived at court, Mr Trump said the trial was "political warfare".
New York's attorney general is seeking a $250m (£202m) fine and a ban on Mr Trump doing business in the state.
Mr Trump denies wrongdoing in a case that could see him stripped of some corporate holdings and signature properties such as Trump Tower.
The judge has already ruled that the former president, along with his two oldest sons - Donald Trump Jr and Eric Trump, who testified last week - and other Trump Organization executives, committed fraud. These proceedings will determine potential penalties.
Arriving at court on Monday, Mr Trump maintained that no fraud had taken place.
Instead, the frontrunner for next year's Republican presidential nomination characterised the entire trial as a politically motivated attempt at "election interference".
"These are political operatives that I'm going to be dealing with right now," he said. "It's a very sad situation for our country. We shouldn't have this."
As Mr Trump began testimony, Judge Engoron said: "Please just answer the questions, no speeches.
"Some of your answers have not been responsive to the questions."
Mr Trump later told the court: "I'm sure the judge will rule against me because he always rules against me."
Judge Engoron told the former president: "You can attack me, whatever you want, just answer the questions."
It is unprecedented for a former president to take the witness stand, presidential historian Lindsay Chervinsky told the BBC.
She said Mr Trump's testimony goes against every political communications strategy in history.
"A president's speech is supposed to be fairly carefully curated," she said. "In a trial, you never know what's going to come up."
Until now, Mr Trump has not testified publicly in any of the other ongoing legal cases against him.
But he has previously clashed with Judge Engoron, who twice ruled that Mr Trump had violated a gag order forbidding him from criticising court staff and fined him $15,000, total.
In Monday's turn on the witness stand, he is to face a grilling, under oath, about evidence the trial has heard that he directed asset values to be fraudulently inflated so his company could secure favourable loans.
The former president has frequently attended the trial in person and shared his displeasure about his former lawyer Michael Cohen, the judge, the attorney general, and even court employees throughout the trial.
When Mr Cohen testified against him, Mr Trump abruptly left court after the judge ruled against him. Apparently caught off-guard, his Secret Service detail hurried to catch up with him.
Will Trump plead the 5th?
Mr Trump is no stranger to court cases. He has been involved in a number of legal disputes over the years, ones that have at times led to him taking the stand or giving depositions.
He has previously invoked his constitutional right against self-incrimination, known as pleading the fifth, in this case.
The Fifth Amendment to the US constitution states that no individual can be "compelled in any criminal case to be a witness against himself".
While testifying under oath in a deposition, which is out-of-court oral testimony, Mr Trump pleaded the fifth more than 400 times but did answer some questions.
That does not mean he will do the same on the witness stand.
Eric Trump invoked that particular constitutional right more than 500 times while testifying under oath in a deposition, but that did not stop him from sparring with state's attorneys when he took the witness stand in court.
What's happened in the trial so far?
There have been several remarkable moments in the Trumps' court case.
His sons' turns on the stand were particularly memorable. Both maintained their innocence.
Donald Trump Jr cracked jokes. "I should have worn make-up," he said to photographers and asked a court sketch artist to make him "look sexy".
There are others testifying in the case as well.
Another co-defendant is former Trump Organization chief financial officer Allen Weisselberg, who has previously pleaded guilty to tax crimes.
Jeff McConney, a Trump Organization executive from 1987 until February this year, was granted immunity in this case to flip against the Trumps. He testified that he had helped company executives avoid taxes and inflated the former president's assets.