President Donald Trump has retweeted an audio recording that US intelligence officials have described as being part of a Russian campaign to denigrate Democratic presidential candidate Joe Biden. The leaked conversation, purportedly between Biden and former Ukrainian President Petro Poroshenko, dates from February 18, 2016. The excerpt of it retweeted by Trump centers on the ouster of Ukraine's chief prosecutor, who had previously investigated the owner of a Ukraine energy company where Biden's son, Hunter, once held a board seat.