United States Vice President Joe Biden on Wednesday assured key ally Australia there would be no retreat from Washington's pivot to the Asia-Pacific region regardless of who wins November's presidential election.

Biden dismissed concerns that Republican presidential nominee Donald Trump would abandon President Barack Obama's strategy for the Asia-Pacific if he were to defeat Democratic nominee Hillary Clinton.

"Don't worry about our election. The better angels in America will prevail," Biden said in a speech in Sydney. "The United States is all in. We've made good on that promise and continue to make good on that promise. We have shown our commitment to lead the region over and over again."