TOKYO — Japan may need to accelerate interest-rate increases if inflationary pressures continue to build, a senior Bank of Japan policymaker warned on Thursday, adding to expectations that the central bank could tighten monetary policy again this month.

Bank of Japan board member Kazuyuki Masu said underlying inflation was approaching the central bank’s 2% target and argued that policymakers should remain prepared to respond if price pressures become broader or more persistent.

A key concern is the combination of higher energy costs and a weaker yen. Rising fuel and chemical prices linked to disruptions caused by the conflict in the Middle East could increase transportation and production expenses, eventually putting additional pressure on consumer prices.

Japan’s monetary policy remains closely watched by international investors. The BOJ has maintained relatively accommodative financial conditions compared with several other major central banks, but expectations of further rate increases have strengthened as inflation concerns have grown.

The yen has also recently gained ground against the U.S. dollar as investors anticipate tighter Japanese monetary policy. Markets are now watching the BOJ’s upcoming policy meeting for indications about the timing and pace of future increases.

A faster tightening cycle could have consequences beyond Japan. Higher Japanese interest rates can influence global currency flows, bond markets and investment strategies, particularly because the yen has traditionally been an important funding currency for international investors.

At the same time, Japanese policymakers face a delicate challenge. Raising rates too quickly could place additional pressure on households and companies that have benefited from relatively inexpensive borrowing, while moving too slowly could allow inflation to become more deeply embedded.

The latest comments therefore reinforce the growing possibility of further monetary tightening. Investors will be looking closely at upcoming economic data and official BOJ statements for evidence of how quickly Japanese policymakers intend to respond to the changing inflation environment.