Tony Abbott says Washington has alienated mainstream voters, which has led to the rise of Donald Trump.
"When you don't have strong mainstream representation, when you don't have credible mainstream leadership, you get less credible leadership offering itself," he told an audience in Singapore on Wednesday.
"There appears to be a degree of popular alienation from Washington in general and the leadership of both major parties."
Trump, who is contesting for the Republican presidential candidacy, has called for the United States to ban Muslims from entering the country.
Trump has called for a "total and complete shutdown of Muslims entering the United States until our country's representatives can figure out what is going on".
The former prime minister did not comment on Mr Trump's comments other than to say he would be "an interesting person" to be the leader of the United States given the "sorts of things that he said".
