The former prime minister has shrugged off an excerpt from the memoirs of former US Defence Secretary Robert Gates, in which Dr Gates fell asleep while listening to Mr Rudd talk.

In his book Duty: Memoirs of a Secretary at War, to be released next week, Dr Gates recalls how a mix of drugs for a broken shoulder, jet lag and wine saw him doze off while Mr Rudd gave "a long soliloquy" about Australian history during a 2008 dinner.

The former Defence secretary writes that the then prime minister was "very gracious about the whole thing". But on Thursday, a spokeswoman for Mr Rudd had a more pointed take on the incident.

"Given the the number of pain-killing drugs [Dr Gates] was on when he arrived at the Lodge, Mr Rudd thought it was surprising Mr Gates could remember anything from the evening at all," she said.

"Perhaps Mr Gates should have taken up Mr Rudd's suggestion, made to him when he arrived, to forget dinner and just go home to bed."

The former prime minister was not without understanding, however.

"Mr Rudd also recalls nodding off a few times himself over the years as foreign minister when the body clock kicked in at the wrong time," the spokeswoman said.

In Duty, Dr Gates, who was Defence Secretary from 2006 to 2011, describes how he slipped on ice outside his house a week before his trip to Australia, breaking his shoulder in three places.

He notes that while he was lucky that the injury didn't need surgery, it still caused some "awkward moments" during his travels.

"At a very nice dinner given in my honour by Australian prime minister Kevin Rudd, I was doing fine at table conversation until Rudd began a long soliloquy on the history of Australia. I had made it just past World War I when the combined effect of a painkiller, jet lag, and a glass of wine caused me to fall asleep," Dr Gates writes.

"This led to not-so-subtle attempts by my American colleagues at the table to rouse me."

While Mr Rudd may not be happy about having the whole world find out about his boring conversation, he got off a lot more lightly in the book than US President Barack Obama - who is accused of not believing in the US strategy in Afghanistan.