Japan's closely watched core inflation slowed in August, pointing to a slight easing in underlying price pressures even as headline inflation remained steady.

The core consumer price index, which excludes fresh food, rose 1.7% year over year in August, down from 1.8% in July, according to data from the Statistics Bureau released Friday.

The reading missed the consensus forecast of 1.8% growth tracked by Investing.com.

On a seasonally adjusted basis, the core CPI increased 0.1% from the previous month.

The headline CPI rose 1.9% year over year, unchanged from July, while the seasonally adjusted index was flat from the previous month.

A measure excluding both fresh food and energy rose 1.9% year over year, matching July's pace, and increased 0.3% from the previous month.

Food prices remained a key source of upward pressure. Prices excluding fresh food rose 3% year over year, while fresh food prices increased 7%. Fresh fish and seafood prices climbed 13.5%, while fresh vegetables rose 5.5%.

Among other categories, housing-related costs increased 3.1% year over year, while furniture and household goods prices rose 1.2%. Transport and communications costs increased 3.7%.

Energy prices, however, continued to weigh on headline inflation. Energy prices fell 0.7% year over year, with electricity prices down 2.4% and gasoline prices down 2.6%.

Education costs provided another drag, falling 6.4% year over year, largely reflecting a 73.2% decline in private high-school tuition.

The data comes ahead of the Bank of Japan's policy decision, with all BOJ watchers surveyed by Bloomberg expecting the central bank to raise its benchmark rate to 1.25% from 1% at the end of its two-day meeting.

If delivered, it would mark the second rate increase in three months and the shortest interval between hikes since March 1990.