* Harold Holt and Lyndon Johnson

Holt coined the phrase "All the way with LBJ" during a June 1966 US visit, endorsing America's approach to the Vietnam conflict. LBJ visited Canberra, Melbourne, Sydney, Brisbane and Townsville in October 1966. Johnson made such an impression that children and streets were named after him. LBJ attended Holt's funeral the following year.

* John Howard and George W Bush

Howard had already been feted in Washington DC for several days when the September 11 terrorist attacks occurred. A day later he addressed a joint sitting of the US Congress and became one of Bush's strongest supporters as the US weighed up military action. Bush addressed the Australian parliament in 2003 and returned four years later for APEC in Sydney. Howard was the last Australian leader honoured with a state banquet at the White House.

* Julia Gillard and Barack Obama

In March 2011, Gillard kicked a footy with Obama at the White House and received a rare invitation to do a Washington DC school visit with the President where they joked about Vegemite. Later that year Obama visited Canberra and Darwin to sign a major defence deal involving marines rotating through the Top End. They are both believers in the power of education.

* Scott Morrison and Donald Trump

Morrison has only been PM since August 2018 but has developed a strong personal relationship with Trump, having spoken with him at several global summits since then. They dined together on the eve of the G20 in Japan in June. Morrison will get "state" treatment with a banquet, Oval Office talks and attendance (along with Jenny) with the President and First Lady at a number of events.

Australian Associated Press