President Trump's son-in-law and adviser Jared Kushner "appeared to be unimpressed and hung up" on an adviser to the late Sen. John McCain after being told that he should treat McCain with respect, according to a new book.

A description of the 2016 encounter was published Tuesday in Kushner, Inc., coinciding with Trump's renewed assault on the Arizona Republican, who died in August.

Kushner, widely viewed as a more diplomatic Trump surrogate, bashed McCain shortly after the 2016 election, according to author Vicky Ward, upset about McCain saying a "reset" with Russia would be "unacceptable."

Kushner called McCain adviser Rick Davis to vent, reportedly saying: "Has McCain got a strategy or is he just an egomaniac?”

He then warned Davis that McCain "does not want to get on Donald Trump’s radar screen.”

“He needs to step back. We have a plan. He ought to give us time to implement our plan. He’s being obstructionist," Kushner reportedly fumed.

Surprised, Davis "recommended that Kushner treat McCain with some respect," according to the book, arguing that "previous presidents had found it worth their while to engage with McCain one-on-one."

"Kushner appeared to be unimpressed and hung up," the book reports.

McCain died of brain cancer last year but has remained a political punching bag for Trump, who in 2015 controversially argued that McCain was "not a war hero."

Trump resumed his attack on McCain on Tuesday, saying in the Oval Office, "I was never a fan of John McCain and I never will be," citing his 2017 vote against repealing Obamacare.

[Opinion: I have always been a fan of John McCain, and always will be]