Chinese shares were down on Wednesday as investors turned cautious ahead of US President Donald Trump's July 9 tariff deadline.

The Shanghai Composite Index, the main gauge of Chinese stocks, inched down 2.95 points to 3,454.79. The Shenzhen Component Index fell 0.6% to 10,412.63. Both indices reversed the previous day's gains.

Trump said he is not considering any delays in raising tariffs, which are part of a package he imposed in April, citing a lack of reciprocity in trading ties.

In other economic updates, resale home prices in China were 0.8% lower in June compared with May, and were 7.3% below what they fetched the same time last year, according to a survey by China Index Academy.

Meanwhile, the growth in the prices of new homes slowed to 0.2% in June versus the 0.3% witnessed in May.

In company news, Jiangsu Alcha Aluminium Group (SHE:002160) unit Shanghai Langmai Clean Technology signed a 165-million-yuan contract covering the renovation of the cleanroom, installation and supply of electromechanical equipment for the Phase 1 of the HPV 9-valent Bulk Solution Workshop of Kangleweishi (Kunming) Biotechnology's recombinant vaccine clinical and industrial base. Shares of the aluminum processor closed more than 2% higher Wednesday.