Former White House strategist Steve Bannon called a meeting between President Trump’s son Donald Jr. and a group of Russians “treasonous” and “unpatriotic,” according to a report Wednesday.

After reports revealed the meeting at Trump Tower in June 2016, Bannon reacted with disbelief, according to the Guardian, citing a new book about the Trump administration.

“The three senior guys in the campaign thought it was a good idea to meet with a foreign government inside Trump Tower in the conference room on the 25th floor — with no lawyers. They didn’t have any lawyers,” Bannon told author Michael Wolff during an interview for his book, “Fire and Fury: Inside the Trump White House.”

“Even if you thought that this was not treasonous, or unpatriotic, or bad s–t, and I happen to think it’s all of that, you should have called the FBI immediately,” Bannon said, according to the book.

Bannon, who joined the Trump campaign three months after the gathering, also speculated that Donald Jr. would have taken the group to his father’s office in the Manhattan high-rise.

“The chance that Don Jr. did not walk these jumos up to his father’s office on the twenty-sixth floor is zero,” he said, something the president has denied happening.

The meeting with Russian lawyer Natalia Veselnitskaya, who had ties to the Kremlin, and other Russians was attended by Trump’s son-in-law Jared Kushner, then campaign chairman Paul Manafort and Donald Jr.

The president’s son agreed to the meeting after being promised by a British music publicist with ties to a Russian oligarch that they had information that “would incriminate Hillary [Clinton] and her dealings with Russia and would be very useful to your father.”

Trump Jr. responded in an email: “I love it.”

Bannon, according to the book, said any meeting should have taken place “in a Holiday Inn in Manchester, New Hampshire, with your lawyers who meet with these people.”

Any dirt on Clinton that came out of the sitdown could then “be dump[ed] … down to Breitbart or something like that, or maybe some other more legitimate publication,” Bannon said.

“You never see it, you never know it, because you don’t need to … But that’s the brain trust that they had,” he told Wolff.

He also predicted special counsel Robert Mueller, who is investigating Russian interference in the 2016 election and whether Trump campaign associates colluded with Russia, would focus on money laundering and follow a trail left by Manafort, Kushner and Trump Jr.

“You realize where this is going,” Bannon is quoted as saying in the book, which is expected to be published next week. “This is all about money laundering.

Mueller chose [senior prosecutor Andrew] Weissmann first and he is a money-laundering guy. Their path to f—–g Trump goes right through Paul Manafort, Don Jr. and Jared Kushner. … It’s as plain as a hair on your face.”

He also predicted: “They’re going to crack Don Junior like an egg on national TV,” referring to the election probe.

Mueller, named special counsel after Trump fired former FBI Director James Comey in May 2017, indicted Manafort on charges of money laundering and tax fraud in October. He pleaded not guilty.

Michael Flynn, Trump’s former national security adviser, pleaded guilty in December to lying to the FBI about his conversations with Russian Ambassador Sergey Kislyak and is cooperating in the probe.