The US is one of Australia's main allies, although their ties have seen some uncertainty after Trump took office last year. In his first phone call with Turnbull, Trump called an Australia-US refugee resettlement agreement a "dumb deal".
Australia is the only country in the world to have fought alongside the US in every major conflict since World War One. The two countries are both part of the "Five Eyes" intelligence alliance, one of the world's most comprehensive intelligence-sharing arrangements.
In trade, the US is the largest source of foreign investment into Australia. Since 2007, China has overtaken Japan as Australia's largest trading partner, with bilateral trade hitting a record 155-thousand Australian dollars in 2017.