Recent exemptions to sweeping US import tariffs may be short-lived, top officials warned Sunday, as China urged the Trump administration to simply abandon its aggressive trade tax policy altogether.

The world's two largest economies have been locked in a fast-moving, high-stakes game of brinkmanship since US President Donald Trump launched a global tariff assault that particularly targeted Chinese imports.

Tit-for-tat exchanges have seen US levies imposed on China rise to 145 percent, and Beijing setting a retaliatory 125 percent band on American imports.

The US side appeared to dial down the pressure slightly on Friday, listing tariff exemptions for smartphones, laptops, semiconductors and other electronic products for which China is a major source.

But Beijing's Commerce Ministry said the move only "represents a small step" and insisted that the Trump administration should "completely cancel" the whole tariff strategy.

The new exemptions will benefit US tech companies like Nvidia and Dell as well as Apple, which makes iPhones and other premium products in China.

Short-lived relief?

The relief could, however, be short-lived with some of the exempted consumer electronics targeted for upcoming sector-specific tariffs on goods deemed key to US national defense networks.

Trump has said he will give "very specific" details on Monday, and his commerce secretary, Howard Lutnick, said semiconductor tariffs would likely be in place "in a month or two."

The US president sent financial markets into a tailspin earlier this month by announcing sweeping import taxes on dozens of trade partners, only to abruptly announce a 90-day pause for most of them.

China was excluded from the reprieve.

The White House says Trump remains optimistic about securing a deal with China, although administration officials have made it clear they expect Beijing to reach out first.

Trump's trade representative Jamieson Greer told CBS "Face the Nation" on Sunday that "we don't have any plans" for a talk between the president and his Chinese counterpart Xi Jinping.

China looks elsewhere

China has sought to present itself as a stable alternative to an erratic Washington, courting countries spooked by the global economic storm.

Xi on Monday kicks off a five-day Southeast Asia tour for talks with the leaders of Vietnam, a manufacturing powerhouse, as well as Malaysia and Cambodia.

The fallout from Trump's tariffs — and subsequent whiplash policy reversals — has sent particular shockwaves through the US economy, with investors dumping government bonds, the dollar tumbling and consumer confidence plunging.

Adding to the pressure on Trump, Wall Street billionaires — including a number of his own supporters — have openly criticized the whole tariff strategy as damaging and counterproductive.

The White House insists the aggressive policy is bearing fruit, saying dozens of countries have already opened trade negotiations to secure a deal before the 90-day pause ends.

"We're working around the clock, day and night, sharing paper, receiving offers and giving feedback to these countries," Greer told CBS.