TOKYO, May 14 : The Bank of Japan should raise interest rates as soon as possible if there are no clear signs of an economic slowdown, Kazuyuki Masu, a member of the central bank's board, said on Thursday, pointing to mixed views at an April policy meeting. The remarks by Masu, who voted to keep rates steady in April, suggest he may join the dissenters to call for a rate hike at the BOJ's next meeting in June as surging oil costs from the Middle East war heighten inflationary pressures. "I myself judge that the situation did not warrant a hasty hike," Masu said in a speech. "That said, if data do not indicate clear signs of an economic downturn, I believe it is desirable to raise rates at the earliest stage possible." The BOJ kept its policy rate steady at 0.75 per cent last month, but three of the nine board members dissented and called instead for a hike to 1.0 per cent, in a sign of growing alarm over inflationary pressures from the Iran war-driven energy shock. A slew of recent hawkish signals from the BOJ have led markets to price in roughly a 70 per cent chance of a rate hike in June. Nearly two-thirds of economists polled by Reuters before last month's meeting had also predicted a rate hike by June. Concern over inflationary risks pushed the yield on the benchmark 10-year Japanese government bond to a 29-year high of 2.605 per cent on Thursday, as high fuel costs add to already building price pressures from the weak yen and steady wage gains. While rising prices of fuel and chemical goods caused by the Iran war could prove a temporary shock, there was concern they could push up already rising distribution costs and lead to enduring price pressures, Masu said. "As the behaviour that took root during the period of deflation is now being unentrenched, Japan has clearly entered an inflationary phase," he added. "Therefore, what is vital from now on is to ensure that, through timely and appropriate policy rate hikes, the underlying inflation rate does not exceed 2 per cent." Masu said underlying inflation remained below 2 per cent but was "drawing very close" to that level. He also said the BOJ must be vigilant to the risk the weak yen could accelerate price rises and heighten the public's inflation expectations. "Given that Japan's economy is no longer in a deflation, the BOJ must pull real interest rates out of negative territory as soon as possible," Masu said. The BOJ needs to raise rates closer to levels deemed neutral to the economy, seen as somewhere in a range of 1.1 per cent to 2.5 per cent, so it can respond swiftly to any inflation spike, he added. The BOJ exited a decade-long massive stimulus in 2024 and raised its policy rate several times, including in December, on the view that Japan was on the cusp of durably achieving its inflation target of 2 per cent. Soaring energy costs from the Middle East conflict have complicated the BOJ's rate decisions as they push up prices, but also hurt an economy heavily reliant on fuel imports. Masu's hawkish tone turns the market's attention to a speech on May 21 by another board member Junko Koeda, who voted for keeping rates steady in April. Deputy Governor Ryozo Himino will also deliver a speech on Saturday.