Prime Minister Malcolm Turnbull has paid tribute to America's war dead on his first excursion in Washington.
Mr Turnbull visited the Arlington War Cemetery in the US capital on Monday morning (US time).
A 19-gun salute boomed out over thousands of white stone war graves, some still with Christmas wreaths.
There were 277 US defence personnel, carrying bayonets attached to rifles and sabres, forming a guard of honour for the prime minister, as well as a 39-member military band.
US Defense Secretary Ash Carter and Major General Bradley A Becker, commanding general of the US Army military district of Washington, accompanied Mr Turnbull up the steps to the tomb of unknown soldiers.
Three US soldiers carried the Australian flag behind the trio.
With bare, gloveless hands on a cold winter's morning, Mr Turnbull hung a floral wreath on a stand in front of the tomb and put his hand over his heart in a moment of quiet reflection.
The national anthems of America and Australia were supposed to be played, however that protocol was swiftly abandoned because of the bitter cold.
It was -7C but felt like -15C with the windchill factor.
Mr Turnbull briefly toured a museum of war photographs and artefacts and shook hands with a US serviceman.
He was presented with a crystal replica of the Tomb of the Unknowns and a copy of the Arlington National Cemetery book, Where Valor Rests.
The prime minister presented the museum with gifts from the Australian War Memorial in Canberra: a coin collection commemorating the 100th anniversary of the Anzac campaign and a book celebrating 100 years of the Australian and American military alliance.
"From our war memorial to you in recognition of our service and history together," Mr Turnbull said.
The military bells and whistles ceremonial welcome continued for Mr Turnbull outside the Pentagon, where he and Mr Carter held bilateral talks.
Global security and military efforts to defeat Islamic State are set to dominate talks during Mr Turnbull's two-day official visit in the US.