THE JAPANESE national flag is hoisted atop the headquarters of Bank of Japan in Tokyo, Japan Sept. 20, 2023. 鈥 REUTERS

THE Bank of Japan (BoJ) is widely expected to keep interest rates unchanged on Tuesday, setting up a communication challenge for BoJ Governor Kazuo Ueda as the foundering yen hovers near levels that have prompted past interventions.

Just weeks ago, markets and economists were betting Mr. Ueda and his board would press ahead with their normalization efforts and deliver another hike at the end of their two-day meeting on Tuesday. Those bets dissipated as US President Donald J. Trump鈥檚 war on Iran sent oil prices surging, with markets now pricing just a 7% chance of a move, and many economists switching to a June increase.

Assuming there鈥檚 no shock 鈥 which can鈥檛 be ruled out as people familiar with deliberations have said the final decision will be made at the last possible moment 鈥 focus will rapidly shift to Mr. Ueda鈥檚 policy signals. The statement usually lands around noon in Tokyo, with Mr. Ueda鈥檚 press conference typically starting at 3:30 p.m.

鈥淭he key thing is how strongly the BoJ will communicate their determination to continue rate hikes to curb the yen鈥檚 depreciation,鈥 said Shigeto Nagai, former head of the BoJ鈥檚 international department.

The currency was hovering around 楼159.50 per dollar early Monday in Tokyo, not far from the level where authorities last intervened to support the yen in 2024. At a Bloomberg New Voices event in Tokyo on Thursday, Finance Minister Satsuki Katayama warned that officials are in close contact around the clock with their US counterparts as Tokyo remains on high alert over speculative moves that are weighing on the yen.

Last week, people familiar with planning told Bloomberg that the BoJ was leaning toward keeping its policy rate unchanged at 0.75% given uncertainties stemming from the war in Iran. Officials are still committed to raising borrowing costs sooner or later, they said.

But differing viewpoints suggest the possibility of a widening divergence among the board鈥檚 nine members, who voted 8-1 to hold policy settings steady at the last meeting in March.

Volatility tied to the Iran conflict has heightened uncertainty around energy costs and supply-chain durability, making it difficult for policymakers to pull the trigger on their next hike.

鈥淭here are limits to how hawkish the BoJ鈥檚 communication can be,鈥 said Naka Matsuzawa, chief strategist at Nomura Securities. 鈥淚t is unclear whether Japanese authorities will be able to contain yen depreciation and bond curve steepening in the run-up to the next meeting in June.鈥

The yen鈥檚 three-month option-implied volatility fell to a two-year low last week as speculation of potential intervention capped downside risks.

Memories remain fresh among market participants of Mr. Ueda鈥檚 press conference in April 2024, after authorities held settings steady. The governor鈥檚 comments on the yen were taken as dovish, sparking a rout in the currency that ultimately prompted intervention days later. Mr. Ueda will be keen to avoid repeating that experience this week.

The US Federal Reserve and European Central Bank also meet this week and are widely expected to stand pat. The BoJ鈥檚 pressure to sustain monetary normalization is driven in part by the ongoing gap with its peers and the fact that real rates that factor in inflation remain deeply negative.

An updated quarterly economic outlook to be released with the policy statement should help justify an ongoing hawkish stance. The BoJ board is likely to consider a sharp increase in its price outlook for the fiscal year that started this month from the latest projection of 1.9%, people familiar with the matter told Bloomberg earlier this month.

鈥淲e see the risk of upward pressure on prices as greater than the hit to growth, given firms鈥 increasingly proactive pricing behavior and the intensifying depreciation pressure on the yen,鈥 said Shotaro Mori, senior economist at SBI Shinsei Bank Ltd.

Japan鈥檚 inflation quickened in March for the first time in five months, data Friday showed. A separate gauge showed service producer prices rose 1.25% from a month earlier, the most in about 36 years excluding periods when there was a hike in the sales tax.

Meantime, sentiment among consumers has tumbled by the most since the Covid pandemic, foreshadowing a looming blow to demand. The median estimate of analysts is for the BoJ to cut its growth projection for this year to 0.8% from 1%.

鈥淚t will be important to see how the economic outlook is revised to assess how policymakers view the downside risks to growth from higher oil prices and, in turn, their impact on underlying inflation,鈥 said Naoya Hasegawa, chief bond strategist at Okasan Securities.

Mr. Ueda entered the fourth year of his governorship this month. In that period he鈥檚 dismantled yield curve control, ended negative interest rates, and lifted policy rates to their highest in three decades.

鈥淗e has only two years left,鈥 said Toshitaka Sekine, a former BoJ chief economist. 鈥淗e has done what鈥檚 needed and he will keep doing it when it鈥檚 necessary.鈥 鈥 Bloomberg