The Bank of Japan dug its heels in on its easy-money policies Thursday while raising its inflation forecast, even as other countries hike interest rates to tackle soaring prices.

Policymakers have refused to move away from measures put in place a decade ago as the BoJ battles to achieve sustained price rises in the world's third-largest economy.

But the decision leaves it increasingly alone as its peers raise rates, sending the yen tumbling to a 24-year low against the dollar.

Highlighting the different approaches, the European Central Bank is later Thursday expected to announce its first rate increase since 2011.

Prices are rising in Japan, and the BoJ raised its inflation forecast for fiscal 2022-23 to 2.3 percent, up from 1.9 percent in April, "due to rises in prices of such items as energy, food, and durable goods".

"Thereafter, the rate of increase is expected to decelerate" as energy prices stabilise, it said.

The BoJ added that it would hold rates at minus 0.1 percent and continue buying unlimited government bonds to maintain a low cap on long-term yields.

These monetary easing policies are intended to achieve sustained two-percent inflation, a target the bank considers key for stable growth.

The central bank views current price increases, driven by pandemic supply snarls and higher commodity prices linked to the war in Ukraine, as temporary.

So while its counterparts elsewhere are moving to tame inflation, it sees no need to change tack.

While the Bank of Japan has raised its inflation outlook, it continues to keep interest rates rock bottom
While the Bank of Japan has raised its inflation outlook, it continues to keep interest rates rock bottom AFP / CHARLY TRIBALLEAU

"There is no sign of meaningful accelerations in the rate of increase in wages, which is necessary for a sustainable rise of prices," said Ryutaro Kono, chief economist at BNP Paribas.

And some feel rate hikes would not address current inflationary pressure in Japan.

"Higher rates would do little to meaningfully change the situation", Stefan Angrick, senior economist at Moody's Analytics, told AFP.

"Inflation in Japan is driven predominantly by higher prices for imported food and energy, which are beyond the BoJ's reach."

Rate hikes are also not guaranteed to boost the yen, he added, noting that "many other currencies have depreciated against the dollar despite their respective central banks hiking rates."

Following Friday's announcement, the dollar jumped as high as 138.55 yen before easing slightly, though that still compares with 115 yen at the start of the year.

The BoJ cut its economic growth forecast for the current fiscal year to 2.4 percent, down from 2.9 percent in its previous forecast, warning that "extremely high uncertainties" remain, from Covid-19 to the situation in Ukraine.

Speaking Thursday afternoon, Governor Haruhiko Kuroda insisted the bank was committed to its easing policy "until the (price) target is met in a sustainable manner".

He acknowledged that the yen's slump against the dollar was causing some difficulties, by "increasing uncertainties in the outlook, making it hard for companies to plan, which is negative and unfavourable for the economy."

But he emphasised that the currency intervention is the preserve of the finance ministry, and that a weak yen brought benefits for exporters.