A top Japanese government official said Prime Minister Shinzo Abe should delay a planned sales-tax increase, the strongest sign yet that economic weakness is causing concern among those close to the premier ahead of the difficult tax decision. He expressed concern that raising the national sales tax too soon after a damaging April hike could derail an economic recovery. Powerful interests like the Finance Ministry, the Bank of Japan and major corporations want Abe to raise the tax as planned next year to keep Japan’s promise to reduce the biggest debt burden in the industrial world.