Asian stocks staged a tentative rebound on Wednesday, helped by dovish comments from US Federal Reserve chair Jerome Powell and upbeat bank earnings on Wall Street, though simmering China-US trade tensions kept a lid on risk appetite.

The benchmark Hang Seng Index gained 273 points, or 1.08 percent, to open at 25,714.

On the mainland, the benchmark Shanghai Composite Index opened up 0.06 percent at 3,867, while the Shenzhen Component Index opened 0.19 percent higher at 12,919.

The ChiNext Index, tracking China's Nasdaq-style board of growth enterprises, was up 0.29 percent to open at 2,964.

Powell left the door open to further rate cuts on Tuesday and said the end of the central bank's long-running effort to shrink the size of its holdings may be coming into view.

His comments, viewed by some as dovish, lifted markets slightly and reinforced expectations of more easing this year, with roughly 48 basis points worth of cuts priced in by December.

"The Fed may soon be looking to conclude [quantitative tightening] with an announcement at its upcoming October FOMC meeting possible," said Tom Kenny, senior international economist at ANZ, referring to the Federal Open Market Committee, which makes makes key decisions about interest rates and the growth of the United States money supply.

"We expect the Fed to cut by 25bp at both the October and December FOMC meetings."

Solid earnings results from US banking giants and an upward revision of the International Monetary Fund's 2025 global growth forecast also underpinned the market, which had taken a nosedive on renewed signs of strain in Sino-US trade relations.

The MSCI's broadest index of Asia-Pacific shares outside Japan was last up 0.45 percent, while the Nikkei rose 0.8 percent after sliding 2.6 percent in the previous session.

Nasdaq futures and S&P 500 futures edged up about 0.1 percent each.

Still, sentiment remained fragile, with US President Donald Trump saying on Tuesday that Washington was considering terminating some trade ties with China, including in relation to cooking oil.

The United States and China also began charging additional port fees on ocean shipping firms that move everything from holiday toys to crude oil.

Markets have been whipsawed in the past few sessions by a sharp escalation in the Sino-US trade war after Trump announced additional 100 percent duties on Chinese goods in retaliation for Beijing's expanded export controls on rare earths.

"It does suggest that a lasting truce is not going to be easy to achieve. But it's also a reminder as well, that the market does need to be mindful that... they shoot these arrows and then they sort of walk them back," said Tony Sycamore, a market analyst at IG.

Spot gold extended its record-breaking run and was last up 0.9 percent at US$4,179 an ounce, helped by geopolitical and economic uncertainties and the US rate cut expectations. (Reuters/Xinhua)