In his new book, former White House official John Bolton alleges that President Donald Trump dislikes Prime Minister Justin Trudeau and once even instructed his staff to attack him on television, as reported by CBC News.

The former U.S. national security advisor details the tension between the two leaders in his anticipated memoir, The Room Where It Happened, which is set to be released on June 23.

"Trump didn't really like either Macron or Trudeau," Bolton writes, referring to the leaders of France and Canada. "But he tolerated them, mockingly crossing swords with them in meetings, kidding on the straight."

"I assume they understood what he was doing, and they responded in kind, playing along because it suited their interests not to be in a permanent tiff with the U.S. president."

The iconic G7 photo, interpreted in many different angles https://t.co/7nVVwtNeBi pic.twitter.com/vznOF2V6Za

— BNN Bloomberg (@BNNBloomberg) June 11, 2018

Bolton provides unparalleled insight into the G7 meeting that took place in Quebec on June 8-9 2018, in which tensions between the leaders notoriously ran high.

He recalls walking into the meeting, detailing how Macron and Trudeau were pressuring a tired Trump to accept policy provisions he clearly disagreed with.

Bolton also notes that — in his opinion — Trump was unprepared for the G7 meeting and didn't understand the issues being discussed.

President Trump calls Canadian Prime Minister Justin Trudeau "very dishonest and weak," accusing him of making "false statements" and says the US won't sign the G7 joint statement https://t.co/AVZCz2SBlF pic.twitter.com/Txgy2eyddw

— CNN (@CNN) June 10, 2018

And the tension didn't end there.

Bolton describes how Trump later became furious on a flight to Asia to meet with the leader of North Korea, having discovered that Trudeau had once again complained about the U.S. tariffs at a news conference.

Trump responded by sending a flurry of furious tweets withdrawing support for the G7 communiqué, as well as blatantly criticizing Trudeau for being "dishonest" and "weak."

PM Justin Trudeau of Canada acted so meek and mild during our @G7 meetings only to give a news conference after I left saying that, “US Tariffs were kind of insulting” and he “will not be pushed around.” Very dishonest & weak. Our Tariffs are in response to his of 270% on dairy!

— Donald J. Trump (@realDonaldTrump) June 9, 2018

According to Bolton, Trump woke up Secretary of State Mike Pompeo to "throw a fit" over the incident.

Bolton then alleges that Trump asked White House economic adviser Larry Kudlow and fellow White House aide Peter Navarro to attack Trudeau on television.

"Trump's direction [to Kudlow] was clear: Just go after Trudeau. Don't knock the others. Trudeau's a 'behind your back guy,'" Bolton writes.

Navarro subsequently did criticize Trudeau, famously saying on Fox News that there's "a special place in hell for any foreign leader that engages in bad faith diplomacy with President Donald J. Trump."

On the same day, Kudlow said on television that Trudeau "stabbed" the U.S. in the back.

I watched the entire conference live. There was nothing but Trudeau restating what he said publicly on tariffs. He was rational and mild-mannered in his responses to questions. Clearly Kudlow is trying to manufacture outrage to please Trump.

— 🛫 𝐖𝐡𝐢𝐬𝐤𝐞𝐲 𝐑𝐨𝐦𝐞𝐨 🛬 (@SayHeading) June 10, 2018

Trump and Trudeau's relationship has been a roller coaster over the past few years, oscillating between what seems to be a reluctant understanding and thinly-veiled dislike.

Prior to the G7 conference, Trump called Trudeau a "very good guy" and his "new found friend" on his social media account.

After the conference, the relationship seemed to sour. Early December 2019 proved especially rocky after Trudeau was caught on camera bashing Trump with several foreign leaders. Trump immediately fired back at Trudeau by calling the Prime Minister "two-faced" on live television.

The U.S. President also took issue with Canadian broadcasting companies removing his cameo in Home Alone 2.

I guess Justin T doesn’t much like my making him pay up on NATO or Trade! https://t.co/sndS7YvIGR

— Donald J. Trump (@realDonaldTrump) December 27, 2019

Mostly recently, when Trudeau was asked to comment on the U.S. President's decision to teargas protestors in early June, he famously took 21 seconds before responding.

Trudeau did not, however, directly criticize Trump.

"We all watch in horror and consternation at what's going on in the United States," Trudeau said in response. "It is a time to pull people together, but it is a time to listen. It is a time to learn what injustices continue despite progress over years and decades."

Trudeau has not yet commented on Bolton's allegations.