Japan's public debt is expected to swell to a record $13.5 trillion as the government finances reconstruction efforts after the March earthquake and tsunami, reports said Saturday. Japan's debt is already the industrialised world's biggest at around twice its GDP, after years of pump-priming measures by governments trying in vain to arrest a long economic decline. The public debt is expected to reach 1,024 trillion yen ($13.5 trillion) by the end of this fiscal year to March, up 99.75 trillion yen from a year earlier, the Yomiuri daily reported citing, unnamed finance ministry sources. The national debt will inflate as Tokyo plans to issue bonds worth 11.55 trillion yen to finance the reconstruction measures in the disaster-hit northeast, the Yomiuri and NHK public broadcaster said. The government spending for the year to March is also expected to swell to a record 106.40 trillion as the series of extra budgets will exacerbate the nation's already tricky fiscal condition.