In February, the G20 economies vowed to boost global growth by more than USD2 trillion over five years, shifting their focus away from austerity as a fragile recovery takes hold.
But as Australia prepares to host the G20 summit in Brisbane in November, Hockey told The Australian newspaper that more work needed to be done.
"The submissions are not meeting our ambitious target at the moment and I expect that a number of jurisdictions will improve their effort," Hockey told the broadsheet.
G20 finance ministers and central bank governors said in February they aimed to lift their collective gross domestic product by more than two percentage points over the next five years.
In a communique following their meeting in Sydney, the world's top economies said the "realistic" target could be achieved by increasing investment, lifting employment and enhancing trade.
But a report in The Australian Financial Review said modelling showed member countries had committed to reforms that would not go even halfway towards the growth target.
"It comes down to the goodwill around the table," he told The Australian.
"There was, in the end, no disagreement in February and in fact our friends in Germany were, by the time of the Washington finance ministers meeting in April, (German Finance Minister) Wolf Schauble was among the most emphatic supporters of the target."
In April, G20 finance ministers and central bank chiefs pledged to follow up on reforms but there was little firm action on how to stimulate world growth further.
