The 3.1 trillion-yen extra budget cleared the parliament -- dominated by Takaichi's Liberal Democratic Party -- sailing through the upper house by 148 votes to 94.

The budget had been approved by Takaichi's cabinet on Tuesday. She has said the money will go towards easing petrol, electricity and gas costs.

Japan, whose economy is heavily reliant on Middle Eastern fuel imports, has been battling rising prices since Iran blockaded the Strait of Hormuz following US-Israeli attacks in February.

Takaichi announced the supplementary budget plan last month, saying "the situation in the Middle East remains uncertain".

It was drafted "to ensure we're fully prepared financially", she said.

However, Takaichi has also said the government expects to secure a stable supply of oil through to next spring.

She added that alternative supplies of naphtha, an oil by-product used in a wide range of industries, from outside the Middle East have recovered to more than 80 percent of previous levels.

Japan's central bank hiked its inflation forecasts in April and cut growth projections on the rising oil prices.

"The rise in crude oil prices is expected to push up prices, mainly of energy and goods, with moves to pass on wage increases to selling prices continuing," it said.