South Korea's headline inflation cooled more than expected in July, but a surge in core prices to their fastest pace in two and a half years and official warnings over lingering price risks kept policymakers on guard, reinforcing expectations that the Bank of Korea will press ahead with its tightening cycle.

According to data released by the Ministry of Data and Statistics on Tuesday, the consumer price index rose 2.8% in July from a year earlier, down from 3.2% in June and marking a three-month low. The reading came in below the median forecast of 3.0% from a Reuters poll of economists. On a monthly basis, the index declined 0.2% — its first fall in eight months — as petroleum product prices dropped 5.5%. Economists had expected a 0.1% monthly increase, matching June's pace. Both the headline and core readings remained above the Bank of Korea's 2% medium-term inflation target.

The undershoot in both headline and monthly CPI may give the Bank of Korea some breathing room. However, Vice Finance Minister Lee Hyoung-il said upward price pressures continue to persist, citing uncertainty tied to the conflict in the Middle East. His remarks suggest policymakers are not treating the softer print as a green light to ease.

The finance ministry estimated that nationwide fuel price caps reduced July inflation by approximately 0.3 percentage points, a measure that has helped keep headline price growth in check. Looking ahead, the ministry flagged that August inflation is likely to see a one-off boost of around 0.8 percentage points due to base effects from temporary mobile fee discounts introduced a year earlier, suggesting the current soft patch in headline inflation may prove temporary.

The decline in oil prices that contributed to July's softer reading followed crude tumbling to three-week lows on Monday, after President Trump decided to hold off on a fresh attack on Iran in the hope of securing a rapid deal that could boost supply from the Gulf.

Underlying price pressures told a markedly different story from the headline figure. Core CPI, which excludes volatile food and energy prices, rose 2.6% year-on-year in July, accelerating from 2.5% in June and marking its fastest annual increase since December 2023. That acceleration points to building price pressure beneath the surface even as headline inflation moderates on lower fuel costs, and is likely to be the more important signal for rate expectations. South Korea's inflation trajectory is closely watched as an early gauge of price trends across export-driven Asian economies, where pass-through from global commodity moves and currency fluctuations often surfaces before it does in larger regional peers.

The Bank of Korea raised interest rates last month for the first time in three and a half years and signalled further increases could follow, as brisk growth in Asia's fourth-largest economy has continued to stoke concerns over inflationary pressure. With the central bank having only just resumed hiking and flagged more to come, the latest data is unlikely to shift that trajectory — particularly given the ministry's own warning of a one-off inflation boost in August from mobile fee base effects. The next Bank of Korea policy meeting will be watched for whether the combined effect of sticky core inflation and the anticipated August base-effect bump stiffens the central bank's resolve to deliver another rate increase.