After a relatively peaceful couple of days following last week's tariff-fuelled ructions, investors were once again on the defensive as a standoff between the world's top economic superpowers shows no signs of abating.

China did little to soothe worries by saying that US levies were putting pressure on its economy, which data showed expanded more than expected in the first quarter.

A decision by Hong Kong's postal service to stop shipping US-bound goods in response to "bullying" levies added to the unease.

Chip behemoth Nvidia said Tuesday that US officials had told the firm it must obtain licences to ship its new H20 semiconductors to China because of concerns they may be used in supercomputers there, adding the rule would last indefinitely.

The move marks the latest salvo in an increasingly nasty row that has seen Washington and Beijing hit each other with eye-watering tariffs, with the technology sector and security at the heart of the issue.

US levies on other trading partners -- despite being mostly paused -- have sent global markets into a tailspin as governments scramble to cushion themselves from the impact of the measures, with many heading to Washington for talks.

Trump has also kicked off an investigation that could see tariffs imposed on critical minerals such as rare earths that are used in a wide range of products including smartphones, wind turbines and electric vehicle motors.

"Silence is never golden -- it's just the calm before the next chaos cycle. And sure enough, the tape just got rattled again," said Stephen Innes at SPI Asset Management.

"Nvidia dropped the mic, revealing fresh export curbs on AI gear headed to China. Then came the other shoe: Trump ordering a new probe into tariffs on critical minerals. Boom -- just like that, we're back in whiplash mode.

"Welcome to the new normal: one step forward, two tariff probes back."

Nvidia said the chip measures would cost it more than $5 billion. The firm's shares tumbled around six percent in after-market trade, and its Asian suppliers were also hit.

Taiwan titan TSMC shed nearly two percent, Japanese firm Advantest was off more than five percent and SK hynix in South Korea lost more than three percent.

And most broader markets retreated across Asia.

Hong Kong led losses, dropping two percent, while Tokyo, Sydney, Seoul, Taipei, Manila, Bangkok and Jakarta were also down.

Singapore, Mumbai and Wellington rose.

London dipped even as UK inflation slowed more than expected in March, while Paris and Frankfurt also retreated.

A weak dollar, and an ongoing run into safe havens, saw gold spike to a fresh record high of $3,291.81.

As investors look for China and the United States to find some common ground that could ease the tensions, Trump said it was up to Beijing to come to the negotiating table.

"The ball is in China's court. China needs to make a deal with us. We don't have to make a deal with them," said a statement from the president read out by Press Secretary Karoline Leavitt at a briefing.

"There's no difference between China and any other country except they are much larger," she added.

Trump also accused China of going back on a major deal with US aviation giant Boeing -- following a Bloomberg news report that Beijing ordered airlines not to take further deliveries of the company's jets.

Shanghai stocks edged up though traders appeared mostly unfazed by news that the world's number two economy expanded much more than expected in January-March, while retail sales, a key guide of consumption, also came in above forecasts.

The reading comes after analysts said figures Monday revealing China's exports soared more than estimated in March were down to a "frontloading" of orders ahead of Trump's so-called "Liberation Day" tariffs on April 2.

"China's prospects for this year remains muted, as rising tensions with the US lead to weaker exports and investment. That chaos will keep households nervous," said Sarah Tan, and economist at Moody's Analytics.

- Key figures around 0715 GMT -

Tokyo - Nikkei 225: DOWN 1.0 percent at 33,920.40 (close)

Hong Kong - Hang Seng Index: DOWN 2.0 percent at 21,030.28

Shanghai - Composite: UP 0.3 percent at 3,276.00 (close)

London - FTSE 100: DOWN 0.2 percent at 8,232.51

Dollar/yen: DOWN at 142.40 yen from 143.18 yen on Tuesday

Euro/dollar: UP at $1.1364 from $1.1291

Pound/dollar: UP at $1.3268 from $1.3232

Euro/pound: UP at 85.66 pence from 85.30 pence

West Texas Intermediate: DOWN 1.2 percent at $60.62 per barrel

Brent North Sea Crude: DOWN 1.1 percent at $63.99 per barrel

New York - Dow: DOWN 0.4 percent at 40,368.96 (close)

dan/mtp

Nvidia

TSMC - TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY

ADVANTEST

BOEING

INDEX CORP.

Dow