Japan's core consumer prices were expected to show their seventh straight month of annual increases in July, a Reuters poll found, offering the central bank some hope a strengthening economic recovery will gradually lift inflation toward its 2 percent target.

But the projected 0.5 percent year-on-year increase will be well off the Bank of Japan's target and keep the central bank under pressure to maintain its massive monetary stimulus, analysts say.

"The increase is largely due to the effect of rising energy costs. Upward price pressure for other goods remains weak," said Takumi Tsunoda, senior economist at Shinkin Central Bank.

The nationwide core consumer price index (CPI), which includes oil products but excludes volatile fresh food prices, rose 0.4 percent in June from a year earlier.

Core consumer prices in Tokyo, available a month before the nationwide data, were seen likely to rise 0.3 percent in August from a year earlier after a 0.2 percent gain in July, according to economists polled by Reuters.

The government will announce the consumer inflation data at 8:30 Tokyo time on Aug. 25 (2350 GMT Aug. 24).