US Secretary of State Hillary Clinton has paid tribute on Anzac Day to the men and women who have served in Australia and New Zealand's armed forces.

In a statement issued from Washington on behalf of US President Barack Obama, Mrs Clinton sent her best wishes to both countries.

She made special mention of those soldiers who fought in the Pacific during World War II.

"At that time, the Pacific faced an uncertain future but American, Australian, and New Zealand troops joined together and stood up for the tenets of democracy.

"Because of their sacrifices and dedication, today we enjoy countless freedoms," the statement said.