China and the US have agreed to halt additional tariffs as both nations engage in new trade negotiations with the goal of reaching an agreement within 90 days.
The White House announced the breakthrough in the trade dispute on Saturday after President Donald Trump and Chinese President Xi Jinping held high-stakes talks over dinner in Argentina.
Trump agreed not to boost tariffs on $US200 billion ($A273 billion) of Chinese goods to 25 per cent on January 1 as previously announced, while Beijing agreed to buy an unspecified but "very substantial" amount of agricultural, energy, industrial and other products, the White House said in a statement.
China "is open to approving the previously unapproved" deal for US company Qualcomm Inc to acquire Netherlands-based NXP Semiconductors "should it again be presented".
In July, Qualcomm - world's biggest smartphone-chip maker - walked away from a $US44 billion deal to buy NXP Semiconductors after failing to secure Chinese regulatory approval, becoming a high-profile victim of the Sino-US trade dispute.
Speaking to reporters on Air Force One, Trump hailed his agreement with Xi.
"It's an incredible deal," Trump said. "What I'd be doing is holding back on tariffs. China will be opening up. China will be getting rid of tariffs."
He said under the deal China would buy a "tremendous amount of agricultural and other product" from the United States.
"It'll have an incredibly positive impact on farming."
State Councillor Wang Yi, the Chinese government's top diplomat, told reporters in Buenos Aires the two sides believed the agreement "effectively prevented the expansion of economic frictions between the two countries".
"Facts show that joint interests between China and the United States are greater than the disputes, and the need for co-operation is greater than frictions," he said.
US farmers have been hurt by reduced Chinese imports of soybeans and other products.
The White House said if agreement on trade issues including technology transfer, intellectual property, non-tariff barriers, cyber theft and agriculture has not been reached with China in 90 days, that both parties agree that the 10 per cent tariffs will be raised to 25 per cent.
Trump slapped 10 per cent tariffs on $US200 billion in Chinese goods in September. China responded by imposing its own round of tariffs. Trump has also threatened to add tariffs on another $US267 billion of Chinese imports.
Xi also agreed to designate the drug fentanyl as a controlled substance, the White House said. For more than a year, Trump has raised concerns about the synthetic opioid being sent from China to the United States, which is facing an epidemic of opioid-related deaths.
US companies and consumers are bearing part of the cost of the US tariffs on China by paying higher prices for goods, and many companies have hiked prices on imported goods.
