Japan's core machinery orders unexpectedly fell for a second straight month in May as the strong yen and weak demand weighed on corporate profits and spending, pointing to a tepid recovery in the business investment needed for sustainable growth.

Cabinet office data published on Tuesday showed a 1.4 percent fall in core orders, a highly volatile data series regarded as an indicator of capital spending in the coming six to nine months, and fell well short of economists' forecast for a 2.6 percent gain in Reuters poll.