"Even if you thought that this was not treasonous, or unpatriotic, or bad shit, and I happen to think it’s all of that, you should have called the FBI immediately," the newspaper quoted Bannon as saying in the book "Fire and Fury: Inside the Trump White House".
Bannon also says in the book that the Russia investigation will end up focusing on money laundering, according to the report.
"They're [investigators] going to crack Don Junior like an egg on national TV," he added.
The book by Michael Wolff, one of the most anticipated political works of the year, was reportedly written on the basis of over 200 interviews with the president, his inner circle and the administration figures.
The author of "Fire and Fury" quotes mocking Bannon's remark:"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."
Steve Bannon is a former chief executive of the Trump campaign during its last three months and ex-White House chief strategist. However, he held this position for seven months and then returned to the Breitbart News media outlet.
The Meeting Described
The former campaign strategist has spoken about the 2016 meeting, involving Trump's son Donald Jr, his son-in-law Jared Kushner, the campaign manager at that time Paul Manafort and Russian attorney Natalia Veselnitskaya. The talks were allegedly initiated as they wanted to receive confidential information about then Trump's rival in the presidential race Hillary Clinton from Veselnitskaya.
However, how Trump Jr. has explained the issue later, the conversation was focused entirely on the adoption of Russian children by US nationals.
Russian officials, as well as US president Donald Trump, have repeatedly denied the allegations of collusion between Moscow and the campaign and called them absurd.
The report about the meeting was revealed by The New York Times newspaper, in July 2017.