Donald Trump did not know Britain was a nuclear power and thought Finland was part of Russia, an explosive new book claims.

John R Bolton, former US national security adviser, is set to release his long-awaited tell-all book about his time in the White House during Trump's administration.

The White House is attempting to block its publication but advance copies have already been acquired by US media.

It contains several telling allegations, including claims about Trump intervening in criminal investigations to give favours to "dictators he liked".

Trump was acquitted in January of two counts of impeachment after an inquiry alleged he had witheld military aid to Ukraine in order to influence the country's government to investigate political rival Joe Biden.

Excerpts from 'The Room Where It Happened: A White House Memoir' were published in the Wall Street Journal, the New York Times and the Washington Post.

Donald Trump appeared to be unaware the UK is a nuclear power (
Image:
REUTERS)

Bolton's book also shines a light on Trump's alleged ignorance about basic world facts.

It claims Trump did not seem to know Britain is a nuclear power and that the President at one time asked if Finland is part of Russia.

The book recounts a meeting with Theresa May in 2018, when a British official with the then-Prime Minister referred to the UK as a nuclear power.

Trump reportedly said: “Oh, are you a nuclear power?”

Donald Trump and Vladimir Putin shake hands after their summit in 2018 in Helsinki (
Image:
Getty Images)

Bolton claims it was obvious to him that the question “was not intended as a joke.”

The book claims even Trump's current top aids, who are careful to be shown publicly backing the President with unswerving loyalty, in fact ridicule him behind his back.

One account in the book claims Secretary of State Mike Pompeo slipped Bolton a note, which read "He [Trump] is so full of s**t." This was during Trump's famous meeting with North Korean dictator Kim Jong-un.

Bolton writes that Pompeo later dismissed the President's show of diplomacy as having “zero probability of success.”

The test firing of a Trident missile (
Image:
PA)
HMS Vigilant at HM Naval Base Clyde, Faslane. The Vanguard-class submarine carries the UK's Trident nuclear deterrent. (
Image:
PA)

In a withering portrait of the leader of the world's great superpower, Bolton bluntly states that intelligence briefings with Trump were a waste of time.

This was because "much of the time was spent listening to Trump, rather than Trump listening to the briefers.”

Trump is shown to make several statements which are wrong or false and appears to have no overarching vision for his presidency, instead appearing to be driven by his gut instincts which often seem reckless, and even dangerous.

Bolton writes: “His thinking was like an archipelago of dots (like individual real estate deals), leaving the rest of us to discern — or create — policy...That had its pros and cons.”

An aerial view of Helsinki - the capital of Finland (
Image:
Getty Images/iStockphoto)

Bolton is also scathing of Democrats who tried to Impeach Trump, as he says they committed “impeachment malpractice” by limiting their inquiry to Ukraine matter.

He writes that they should have explored how Trump intervend in investigations into companies to curry favour with other dictators.

These include investigations into Chinese firm ZTE and Turkey’s Halkbank.

Northern lights over the Pyhae Luosto National Park in northern Finland (
Image:
Getty Images/iStockphoto)

Reuters reports Bolton said Trump sought Chinese President Xi Jinping's help to win re-election during a closed-door June 2019 meeting.

Bolton, who Trump fired in September after 17 months in the White House job, says Trump expressed a willingness to halt criminal investigations to give "personal favors to dictators he liked."

The accusations in the book saw the US government on Tuesday sue to block Bolton from publishing, arguing it contained classified information and would compromise national security.

Former US National Security Advisor, John Bolton, signed a £2million book deal

Bolton's allegations provide new ammunition to critics just before the November 3 presidential election, including his behind-the-scenes accounts of Trump's conversations with China's Xi - which, in one case, broached the topic of the US ballot.

"Trump then, stunningly, turned the conversation to the coming U.S. presidential election, alluding to China's economic capability and pleading with Xi to ensure he'd win," Bolton wrote, according to excerpts of his book published in the Wall Street Journal.

"He stressed the importance of farmers and increased Chinese purchases of soybeans and wheat in the electoral outcome."

In excerpts published in the Washington Post, Bolton says Trump said invading Venezuela would be "cool" and that it was "really part of the United States."