US President Donald Trump sought help from Chinese President Xi Jinping to win re-election, ex-National Security Adviser John Bolton’s new book says.

Mr Bolton says Mr Trump wanted China to buy agricultural produce from US farmers, according to details of the forthcoming book previewed by US media.

He also says Mr Trump “remained stunningly uninformed on how to run the White House”.

The Trump administration is trying to block the book from hitting shelves.

Speaking to Fox News, Mr Trump said of Mr Bolton: “He broke the law. This is highly classified information and he did not have approval.”

“He was a washed up guy,” the president added. “I gave him a chance.”