Japan's current run of economic growth provides a now-or-never opportunity to tackle the nation's debt and forge ahead with plans to increase the sales tax, said Yoshimitsu Kobayashi, chairman of the Japan Association of Corporate Executives (Keizai Doyukai).

The ballooning debt shows no signs of easing, Kobayashi, 70, said in an interview on Tuesday in Tokyo. He previously advised the government, and his business lobby is an important voice in policy debates. "You've got to do it during good times like this, otherwise, you never will," he said. "We have reached a point where we must consider how to make Japan's fiscal situation sustainable."

When public support for Prime Minister Shinzo Abe plunged earlier this year, some lawmakers started talking about canceling the tax hike, he said. That, and the adoption of an additional measure to assess the nation's fiscal health, are signs that the government's resolve to rein in debt is wavering, said Kobayashi, who is also chairman of Mitsubishi Chemical Holdings Corp.