John Bolton: Trump sought Xi's help with re-election

US President Donald Trump tried to get China's Xi Jinping to help him secure re-election, ex-National Security Adviser John Bolton's new book says.

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

Correspondents say the episode is reminiscent of actions that led to Mr Trump's impeachment.

The Trump administration is trying to prevent publication of the book.

According to the Department of Justice complaint, it contains "classified information".

The book, entitled The Room Where It Happened, is due to be released on 23 June.

In January, the White House said it contained "top secret" details, which must be removed, although Mr Bolton rejected this.