The People's Bank of China has raised interest rates twice in 2011 and many analysts believe it may raise them again soon in an effort to control inflation.

"It will be very difficult for China to cap its annual inflation within 4 percent and the full-year CPI is likely to reach 5 percent," Zhang was quoted as saying by the state radio.

Beijing has set an annual inflation ceiling at 4 percent this year, but prices keep rising stubbornly and many economists have said it will be tough to achieve the goal.

Zhang said his inflation forecast for June also reflected the relatively low ase of comparison of a year earlier.

He attributed the persistent inflationary pressure mainly to an excessive supply of money and credit over a long time, when Beijing rolled out a massive stimulus plan to shield the economy from the financial crisis.

The increases of other input costs for enterprises, such as rising prices of labour and raw materials, will also make this round of inflation last for a while, he added.

According to a Reuters poll of 22 economists, China's consumer price index (CPI) in May may have accelerated to 5.4 percent from 5.3 percent in April.

The National Bureau of Statistics is scheduled to publish monthly economic indicators, including the consumer price index, for May on June 14.

Copyright Reuters, 2011