With the economy growing above its potential rate, the nation needs structural reforms rather than a big dose of government spending, according to Susumu Takahashi, a member of the government's economic and fiscal policy council.

Strong exports and resilient domestic demand have set the economy on the longest run of expansion since 2006. And upcoming data for the quarter through June 30 are likely to show the effect of a previously approved fiscal stimulus package is already trickling in, Takahashi, 64, said in an interview.

"The economy doesn't need a stimulus package right now and there's no reason for a supplementary budget," he said on Tuesday. Takahashi, who is chairman at the Japan Research Institute, said properly targeted spending within the regular budget is sufficient.