Donald Trump has slammed John Bolton as Democrats call for him to testify in the president’s impeachment, claiming he would have helped start four more World Wars had he not been removed from his post.

“Frankly, if I had listened to him, we would be in World War Six by now,” Mr Trump wrote in a series of scathing tweets.

The president also decried Democrats’ attempts to get his former national security adviser — who was ousted in September of last year — to deliver testimony, following a leaked manuscript of Mr Bolton’s upcoming book.

“No matter how many witnesses you give the Democrats, no matter how much information is given, like the quickly produced Transcripts, it will NEVER be enough for them,” Mr Trump wrote on Tuesday night, later retweeting himself and a second tweet that derided Mr Bolton’s claims.

“Why didn’t John Bolton complain about this ‘nonsense’ a long time ago,” he added, “when he was very publicly terminated. He said, not that it matters, NOTHING!”

All the president's lawyers: The team fighting Trump's impeachment Show all 6 1 /6 All the president's lawyers: The team fighting Trump's impeachment All the president's lawyers: The team fighting Trump's impeachment Alan Dershowitz Dershowitz is a controversial American lawyer best known for the high-profile clients he has successfully defended. Those clients have included OJ Simpson, Jeffrey Epstein and Harvey Weinstein. One longtime Harvard Law associated told the New Yorker Dershowitz "revels in taking positions that ultimately are not just controversial but pretty close to indefensible." Getty All the president's lawyers: The team fighting Trump's impeachment Ken Starr Starr became a household name in the 1990s as the independent counsel who led the investigation that led to Bill Clinton's impeachment. That investigation began as a look into a real estate scandal known as Whitewater, and eventually led to impeachment after Mr Clinton lied under oath about having an affair with White House intern Monica Lewinsky. AP All the president's lawyers: The team fighting Trump's impeachment Jay Sekulow Sekulow is the president's longtime personal attorney, and, now, personal lawyer in the White House. He has been accused by former Rudy Giuliani associate Lev Parnas of being "in the loop" during the Ukraine scandal. Getty All the president's lawyers: The team fighting Trump's impeachment Pam Bondi Bondi is the former attorney general in Florida, and a longtime backer of the president's. She made a name for herself in Florida for taking hyper partisan stances on issues, and her penchant for publicity. She is likely to be a prominent public-facing figure during the trial. AFP/Getty All the president's lawyers: The team fighting Trump's impeachment Pat Cipollone Cipollone is the White House counsel, and leading the president's defence team. Getty All the president's lawyers: The team fighting Trump's impeachment Rudy Giuliani While not officially named as one of the president's impeachment lawyers, it is hard to ignore Giuliani's outsized role in this process. The former mayor of New York has been making headlines for months as he defends his client, and for his apparent role in the effort to compel Ukraine to launch the investigation into Joe Biden. We'll see how he figures in the actual trial, which he has said he would like to be a part of. Reuters

The manuscript reportedly revealed Mr Trump demanding political investigations from Ukraine into one of his 2020 political rivals, Joe Biden, while discussing withholding of crucial military aid to the country in conversations with his former adviser.

After it was reported earlier this week, Mr Bolton’s new book revelations added fuel to Senate Democrats’ demands for witnesses in the impeachment trial against the president.

Mr Trump sought to remind his supporters on Wednesday morning that Mr Bolton was apparently bad news, despite appointing him to a prominent role on the national security team in March 2018.

In a long-running sentence, the president attacked Mr Bolton for not being able to “get approved for the Ambassador to the UN years ago” and having allegedly “begged” for a non-Senate approved position.

He went on to list “many more mistakes” made by Mr Bolton, including mocking him over when he “mistakenly says ‘Libyan Model’ on T.V”.

Mr Trump then slammed Mr Bolton for going out “IMMEDIATELY” and writing “a nasty [and] untrue book.”

“All Classified National Security,” he added. “Who would do this?”

Meanwhile, it remains unclear how the new revelations from Mr Bolton’s manuscript will impact Republican senators in their vote on whether to support adding witnesses to the impeachment trial.