Mainland Chinese and Hong Kong stocks opened mixed on Tuesday.

The benchmark Hang Seng Index in Hong Kong rose 39 points, or 0.17 percent, to open at 23,927.

In the mainland, the benchmark Shanghai Composite Index rose 0.04 percent to open at 3,474 while the Shenzhen Component Index opened 0.04 percent lower at 10,431.

The ChiNext Index, tracking China's Nasdaq-style board of growth enterprises, was down 0.03 percent to open at 2,129.

In Tokyo, the Nikkei share average rose, buoyed by a weakening yen and as US President Donald Trump gave an additional three-week grace period for tariff negotiations.

By midday local time, the Nikkei gained 0.2 percent to 39,679 while the broader Topix added 0.1 percent.

Trump reignited his trade war by threatening more than a dozen countries with higher tariffs on Monday – but then said he may be flexible on his new August deadline to reach deals.

In a move that will cause fresh uncertainty in a global economy already unsettled by his tariffs, the 79-year-old once again left the countries room to negotiate a deal.

"I would say firm, but not 100 percent firm," Trump told reporters at a dinner with visiting Israeli Prime Minister Benjamin Netanyahu when asked if the August 1 deadline was firm.

Pressed on whether the letters were his final offer, Trump replied, "I would say final – but if they call with a different offer, and I like it, then we'll do it." (Xinhua/Agencies)