The Diet on Thursday passed a ¥3.04 trillion ($28 billion) supplementary budget for fiscal 2018 to fund measures including the bolstering of defences against natural disasters.
The House of Councilors approved the second extra budget for the year through March following its passage at the House of Representatives earlier this week.
Of the budget, ¥1.07 trillion will be spent on projects to prevent and manage disasters, including shoring up roads and levees, after catastrophes such as a powerful typhoon and earthquakes devastated parts of the country last summer.
A further ¥325.6 billion has been earmarked to improve the competitiveness of farmers in view of the entry into force of free trade deals including the 11-member Trans-Pacific Partnership.
An upswing in tax revenues and leftover funds from the previous fiscal year will cover the bulk of the spending plan, with the government planning to issue just over ¥1 trillion worth of bonds to finance the rest.
The budget comes on top of the initial budget, which climbed to a record ¥97.71 trillion amid swelling social security costs, and an earlier supplementary budget worth ¥935.6 billion.