Asian markets stumbled Wednesday and gold hit a new record as investors kept tabs on China and the United States after they exchanged tariffs, sparking fears of another debilitating trade war between the economic superpowers.

Shanghai, which reopened after a week-long break, and Hong Kong were among the main losers as e-commerce firms took a hit from news that the US Postal Service was suspending inbound parcels from China and Hong Kong.

The tepid performance came despite a positive lead from Wall Street, where there was a sigh of relief that US President Donald Trump had reached a deal to delay 25 percent duties on imports from Canada and Mexico.

Disappointing earnings from Google-parent Alphabet and Advanced Micro Devices added to the unease over the tech sector, which has already been roiled by the unveiling of a new chatbot by Chinese startup DeepSeek.

All eyes were on Washington and Beijing after they renewed their trade spat, though analysts said China's apparently more measured approach provided some hope that a full-blown crisis could be avoided.

"Regarding China's counter measures, we think that the tariffs are less than what we had expected in our view. The move is largely symbolic given that only about 12% of total imports from the US would be subject to tariffs," said Kai Wang, Asia equity market strategist at Morningstar.

"A key takeaway from this development, at least for now, is that fundamentally there is less risk implied than expected before.

"However, escalation of the trade war remains a risk given Trump's history of unpredictable behavior. Therefore, the volatility risk remains on the table for the next four years at least," he added.

Economists at HSBC Global Research added that China's "moves so far are more measured compared with the universal 10 percent tariff imposed by the US, suggesting a likely different playbook than a tit-for-tat strategy, though we acknowledge the risk of escalation has increased".

Hong Kong fell more than one percent, with e-commerce giant JD.com sinking nearly four percent and rival Alibaba also lower on news of the US Postal Service suspension.

Trump's tariff announcement against China included the removal of an allowance — used by China's e-commerce firms — that exempted small packages worth less than $800 from duties. The suspension does not involve letters and flat mail.

Shanghai dropped as it reopened after a week-long break, while Singapore, Wellington, Mumbai, Bangkok and Jakarta also retreated, though Sydney, Seoul, Taipei and Manila rose.

Tokyo reversed earlier losses, though Nissan dived 4.9 percent after Japan's Nikkei business daily said the carmaker had decided to withdraw from merger talks with rival Honda. Shares in Honda surged more than eight percent.

Gold hit a fresh peak of $2,861.93 as investors rushed into the safe-haven metal.

Tech firms were also under pressure after Alphabet sank 7.5 percent in after-hours trade in New York owing to disappointment at its lower-than-expected revenue growth and its ambitious 2025 capital spending forecast.

Advanced Micro Devices also sank in post-close business.

The tech sector has been feeling some pain since DeepSeek's arrival on the scene with its chatbot, which apparently was developed at a fraction of the cost of similar tools made by US firms, stoking concerns about the eye-watering investments made in AI in recent years.

On currency markets, the yen strengthened against the dollar following data showing nominal wages in Japan rose far more than expected last month and at the fastest pace since 1997. 

That firmed expectations the country's central bank would continue to hike interest rates this year.

Key figures around 0710 GMT

Tokyo - Nikkei 225: UP 0.1 percent to 38,831.48 (close)

Hong Kong - Hang Seng Index: DOWN 1.1 percent to 20,570.56

Shanghai - Composite: DOWN 0.7 percent to 3,229.49 (close)

Euro/dollar: UP at $1.0386 from $1.0383 on Tuesday

Pound/dollar: UP at $1.2481 from $1.2480

Dollar/yen: DOWN at 153.17 yen from 154.32 yen

Euro/pound: UP at 83.22 pence from 83.16 pence

West Texas Intermediate: FLAT at $72.68 per barrel

Brent North Sea Crude: DOWN 0.2 percent at $76.08 per barrel

New York - Dow: UP 0.3 percent at 44,556.04 (close)

London - FTSE 100: DOWN 0.2 percent at 8,570.77 (close)