Donald Trump's administration is targeting Julian Assange as an enemy of the America who must be brought down" and his very life could be at risk if he is sent to face trial in the US, the first day of the WikiLeaks founder's extradition hearing has been told. Lawyers for Assange intend to call as a witness a former employee of a Spanish security company who says surveillance was carried out for the US on Assange while he was at Ecuador's London embassy and that conversations had turned to potentially kidnapping or poisoning him. Assange, 48, is wanted in the US to face 18 charges of attempted hacking and breaches of the Espionage Act. They relate to the publication a decade ago of hundreds of thousands of diplomatic cables and files covering areas including US activities in Afghanistan and Iraq. The Australian, who could face a 175-year prison sentence if found guilty, is accused of working with the former US army intelligence analyst Chelsea Manning to leak classified documents. Key parts of the evidence related to the claim, which emerged last week, that a then US Republican congressman offered Assange a pardon if he denied Russian involvement in the leaking of US Democratic party emails during the 2016 US presidential contest. The court was told that Dana Rohrabacher, who claims to have made the proposal on his own initiative, had presented it as a "win-win" scenario that would allow Assange to leave the embassy and get on with his life.