US Vice-President Mike Pence came to Australia to make peace after a rough start to the relationship under new President Donald Trump, but it was North Korea that more than anything united the two long time allies.
The security threat posed by North Korea has dominated Mr Pence's 10-day tour of the Asia Pacific, with the vice president repeatedly saying "all options" are on the table for dealing with Pyongyang.
In Sydney on Saturday he stood alongside Prime Minister Malcolm Turnbull to step up calls on China to do more to pressure North Korea into dumping its nuclear and ballistic missile program.
Last week, Foreign Minister Julie Bishop indicated Australia would consider further sanctions against the hermit state.
It was in response to that threat that North Korea later on Saturday night issued a statement through its official news agency, threatening to attack Australia with nuclear missiles for "blindly and zealously toeing the US line" on the rogue state.
Ms Bishop struck back on Sunday, saying the threat from North Korea could not be left unchecked
"The North Korean government should invest in the welfare of its long-suffering citizens, rather than weapons of mass destruction."
Mr Pence on Sunday remained silent on the war of words between Australia and North Korea as he joined his family for tours of Taronga Zoo, Sydney Harbour, NSW Government House and the Opera House on the final day of their official visit.
But he made it clear on Saturday that the US appreciated Australia's backing on North Korea.
He also reaffirmed the US commitment to the controversial refugee swap deal that had dented the US-Australian relationship during a fiery phone call with Mr Turnbull and Mr Trump shortly after his inauguration.
The vice president confirmation of the deal could be seen as a gift of goodwill.
"It was a deal that they inherited from the Obama administration, and they weren't happy about the detail of the deal, but given the nature of the relationship, they honour the deal and we're very grateful for it," Immigration Minister Peter Dutton told the ABC's Insiders program.
On Sunday, it was Sydney's turn to treat the Pence entourage, with the city showcasing some of its greatest tourist spots.
But while Mr Pence is one of the world's most powerful men, he failed to impress Penny the red kangaroo when he dropped by at the zoo to meet some local wildlife.
Penny was snoozing happily in the shade of a gum tree when Mr Pence, his wife Karen and their daughters Charlotte and Audrey arrived to give her a pat.
"That's my usual position on a Sunday afternoon," Mr Pence joked to Penny's keepers.
There were plenty more photos as the family met Cheezel the ringtail possum, Jindi the echidna, Griffin the sooty owl and Bai'yali the koala before boarding a luxury cruiser, ironically named Enigma, to take to Sydney Harbour.
Accompanied by a large flotilla of boats carrying armed police and Secret Service agents, America's second family were shown around the harbour by NSW Premier Gladys Berejiklian.
The Pence family ended the day sharing afternoon tea at NSW Government House with Governor David Hurley and his family followed by a private tour of the Opera House.
Mr Pence's visit to Australia was hailed by Mr Turnbull, who said it was the earliest visit ever by a vice president in the term of a new US administration.
Mr Pence is due to fly out of Australia for Hawaii early Monday morning.
