US Vice-President Joe Biden has praised what he calls irrepressible ties of "optimism" linking Australia and America.
Mr Biden was guest of honour at a Government House dinner in Melbourne on Sunday night hosted by Governor of Victoria Linda Dessau.
Victorian Premier Daniel Andrews, federal Trade Minister Steve Ciobo and Opposition Leader Bill Shorten were among about 90 local dignitaries to attend.
Musician Archie Roach performed a song as an indigenous welcome to country.
Mr Biden told the audience after a 40 year career in public office - and having meet most world leaders - he remained an optimist.
He said the world was on the verge of technological breakthroughs in areas such as high speed flight.
"We are so much better positioned than any two countries to lead in the 21st century - and I mean that sincerely," Mr Biden said.
He spoke of stories from his grandfather in World War Two and son in Iraq who each served alongside Australian troops.
