Secretary of the Department of Foreign Affairs and Trade Frances Adamson has told the ANU Crawford Australian Leadership Forum that the challenge Australia faces from a rising China is not as big as many Australians perceive it to be.
She also said a recent charm-offensive by visiting US Government officials has done the job in reassuring Australia that America will maintain a strong presence in Asian-Pacific security.
"We have been challenged by our sometimes vivid imagination about some of these things," Ms Adamson said.
"Some of the polling says Australians see a much bigger China emerging than the Chinese themselves see.
"It may be natural for us to do that but I think the reality lies somewhere in the middle. We are also inclined to worry about a US withdrawal.
"I must say, I think we've been genuinely quite heartened and reassured by what both Vice-President Pence has said when he came to the region, and what Secretaries Mattis and Tillerson have had to say, and by what was by any comparison a particularly good Australia-United States Ministerial Consultations in Sydney a couple of weeks ago."
The Crawford Australian Leadership Forum is Australia's leading public policy conference, which brings together 150 experts from politics, government, business and academia.