A new poll of Australian opinions on Donald Trump has revealed a "surprising" gap between what they think of the United States depending on whether he is mentioned.

The poll by the United States Study Centre at the University of Sydney identified a "statistically significant" difference between views of Australian voters and what they thought of American strength over the last 12 months depending on the mention of the President.

Forty-eight per cent of Labor voters and 35 per cent of Coalition voters replied the US was weaker when Mr Trump wasn't mentioned. When he was, those figures jumped to 60 per cent for Labor voters and the Coalition side fell to 29 per cent.

When they were asked their opinion "since the end of the Obama administration", 39 per cent of Coalition voters said the nation was weaker while Labor voters remained steady at 57 per cent.