John Kerry
Mr Kerry spoke on behalf of President Barack Obama and United States of America citizens when he said the Anzac spirit was defined by endurance, courage and "mateship".
"The United States is proud of our enduring cooperation with Australia and New Zealand in pursuit of these common ideals," he said.
"We will forever remember the heroic efforts of 1915 and the brave men and women who made the ultimate sacrifice in defense of freedom."
Countering violent extremism, providing disaster relief, supporting good governance in the Pacific and promoting free trade through the Trans-Pacific Partnership were examples of the countries working together, Mr Kerry said.
