BEIJING -- China is formulating a set of property control measures that will have long-lasting effects, and will unveil the measures at an appropriate time, an official said Tuesday.

"The country's opposition to real estate speculation will not change," Ning Jizhe, deputy head of the National Development and Reform Commission and head of the National Bureau of Statistics (NBS), said at a press conference.

He did not give any timetable for the release of the new measures.

Late last year, China made it clear that "houses are built to be inhabited, not for speculation," according to a document issued after the central economic work conference.

This year, local governments have taken new measures to rein in speculation and promote stable and healthy development of the real estate market, including tougher restrictions on home purchases and obtaining loans.

"Current property curbs will continue to play their roles," Ning said.

In the past few years, first-tier and some second-tier cities took effective measures to rein in rocketing home prices, while smaller cities moved to reduce their housing inventories, he added.

Property sales continued to cool in the first eight months of this year, NBS data showed. In terms of floor area, commercial housing sales gained 12.7 percent, down 1.3 percentage points from January-July.

Meanwhile, the area of unsold commercial housing stood at 623.5 million square meters at the end of August, down by 12 percent from a year earlier.