WASHINGTON — President Donald Trump's former national security adviser, John Bolton, writes in a forthcoming memoir that his former boss made policy decisions in order to help his own political prospects.

"The Room Where it Happened: A White House Memoir," is set to be publicly released on June 23, but news outlets obtained copies ahead of its release and an excerpt was published Wednesday in the Wall Street Journal, revealing that Bolton portrays Trump's foreign policy strategy as "chaotic," and suggests Trump was consumed with re-election.

"The whole thing made my head hurt," Bolton says of Trump's approach to trade.

The Trump administration sought to block the book from being published this week, with the Department of Justice filing a lawsuit in federal court. Trump has also dismissed the book as "highly inappropriate" and said it would be a "criminal problem" if published.

Democrats and other critics of Bolton pointed out that he refused to testify during their impeachment inquiry into the president's dealings with Ukraine, and only agreed to testify during the Senate trial when he knew it was unlikely Republicans would call him forward. 

Trump told the Wall Street Journal in an interview Wednesday night that Bolton "is a liar while adding “everybody in the White House hated John Bolton” in response to the reports on the book.

Here are key claims from Bolton's book, as reported Wednesday:

Trump sought foreign help to help his re-election

As was alleged by Democrats during impeachment, Bolton writes that Trump used his position as president to boost his 2020 re-election chances. But Bolton says, in the published excerpt, that those efforts went beyond just Ukraine. The book is expected to detail other pressure campaigns on governments, according to a book preview released last week by Simon & Schuster.

"I am hard-pressed to identify any significant Trump decision during my White House tenure that wasn’t driven by re-election calculations," Bolton says.

Trump asked China's president Xi Jinping to increase its purchase of American-grown farm products because aiding farmers would benefit him in the presidential race, according to the published excerpt. The requests came during trade negotiations at the 2018 G-20 summit in Argentina and again in June 2019 at the summit in Japan.

"In exchange (for concessions on tariff rates), Trump asked merely for some increases in Chinese farm-product purchases, to help with the crucial farm-state vote," Bolton writes of the Argentina meeting in the excerpt. "If that could be agreed, all the U.S. tariffs would be reduced. It was breathtaking."

And in Japan, Trump "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 writes.

Ukraine aid linked to investigations, Dems should have pursued more

According to The New York Times, Bolton also writes that Trump explicitly linked military aid money designated by Congress for Ukraine to investigations he wanted into Democrats, an allegation at the center of the impeachment investigation.

Trump asked Ukraine President Volodymyr Zelensky to look into former Vice President Joe Biden, his 2020 rival, and House Democrats sought to prove that he did so with the threat of withholding the aid money. Trump repeatedly denied there was a quid pro quo, and he was ultimately acquitted by the Republican-majority Senate.

According to the Times, Bolton writes that on Aug. 20, Trump "said he wasn’t in favor of sending them anything until all the Russia-investigation materials related to (Hillary) Clinton and Biden had been turned over.”

And Bolton criticized Democrats for not looking into other transgressions he says Trump committed, rather than focusing almost exclusively on Ukraine.

"Had Democratic impeachment advocates not been so obsessed with their Ukraine blitzkrieg in 2019, had they taken the time to inquire more systematically about Trump’s behavior across his entire foreign policy, the impeachment outcome might well have been different," Bolton writes in the excerpt published by the Wall Street Journal.

Top advisers mock Trump behind his back

Bolton describes Trump administration officials as denigrating their boss behind his back at times. Some, including Bolton and Pompeo, considered resigning out of frustration with Trump, the Washington Post reported from Bolton's book.

“What if we have a real crisis like 9/11 with the way he makes decisions?” former chief of staff John Kelly said, Bolton writes in the book. 

According to the Times' reporting, Bolton described Trump's 2018 meeting with Kim Jong Un, during which he says Secretary of State Mike Pompeo passed a note to Bolton about Trump that read, "He is so full of s--t."

Trump approved of internment camps in China

Bolton writes that Trump spoke with China's leader about plans of "basically building concentration camps" to hold Uighur Muslims, a religious and ethnic minority group that has been strategically detained by the Chinese government in internment camps and prisons.

The White House announced Wednesday that Trump signed a bill that would punish China for its crackdown on Uighurs, as pieces of Bolton's book came out, including his recalling that Trump approved of the Uighur camps a year ago.

Bolton writes that during the Japan G-20 summit, "with only interpreters present, Xi had explained to Trump why he was basically building concentration camps in Xinjiang."

"According to our interpreter, Trump said that Xi should go ahead with building the camps, which Trump thought was exactly the right thing to do," Bolton said.

The legislation Trump signed "holds accountable perpetrators of human rights violations and abuses such as the systematic use of indoctrination camps, forced labor, and intrusive surveillance to eradicate the ethnic identity and religious beliefs of Uyghurs and other minorities in China," the president said in a White House statement. 

According to the WSJ, Trump denied giving Xi approval for the Uighur camps in China. 

Contributing: Ledyard King; the Associated Press