US Treasury Secretary Steve Mnuchin on Sunday insisted President Trump intends to implement $60 billion in tariffs on Chinese imports, saying the measures will benefit the economy long-term.

Speaking on "Fox News Sunday," Mnuchin said unless a deal is reached with China, Trump will implement the tariffs targeting sectors in which Washington says Beijing has stolen American technology.

"We are going to proceed with our tariffs. We are working on that," he said.

China warned the US on Friday that it was not afraid of a trade war as it threatened tariffs on $3 billion worth of US goods in response to Trump's new measures.

Mnuchin repeated Trump's assertion that "we are not afraid of the trade war" — but added he had had "very productive conversations with the (Chinese) vice premier."

"I'm cautiously hopeful we reach an agreement, but if not we are proceeding with these tariffs. We are not putting them on hold unless we have an acceptable agreement that the president signs off on," he said.

Meanwhile, despite slumps on the stock market in the wake of Trump's announcement, the Treasury secretary said the measures spell long-term benefits for the economy.

"The market will go up and down in the short term (but) the real important issue is where will it be longer-term," Mnuchin said.

"I think what we're doing is, long-term, very good for the economy, which was pressing for free and fair trade and to the extent that China is willing to open up their markets."

"If they open up their markets, it's an enormous opportunity for US companies."

Top Chinese, US officials to continue trade talks: Xinhua
Beijing (AFP) March 24, 2018 –

China's top economic official Liu He spoke by phone with US Treasury Secretary Steven Mnuchin on Saturday and "agreed to continue to communicate" on trade issues, the official Xinhua news agency said.

The call came at a time of heightened tensions after US President Donald Trump on Thursday authorised tariffs on as much as $60 billion of Chinese imports, targeting sectors in which Washington says Beijing has stolen American technology.

Liu He, a Harvard-educated Communist Party official who was elevated on Monday to the key role of vice premier, is expected to oversee China's financial and economic sectors.

On the phone, he accused a US investigation of violating international trade rules and told Mnuchin that Beijing was ready to defend its interests, Xinhua said.

"China is ready to defend its national interests and hopes that both sides will remain rational and work together to safeguard the overall stability of China-US economic and trade relations," Xinhua cited Liu as saying.

China warned the US on Friday that it was "not afraid of a trade war" as it threatened tariffs on $3 billion worth of US goods in retaliation to Trump's new measures.

It unveiled a hit list of products from fresh fruit to pork that could face duties of up to 25 percent, though it stopped short of pulling the trigger as it indicated its readiness to negotiate an agreement.

In August, the US formally launched a trade investigation into China's intellectual property practices and the forced transfer of US technology under Section 301 of US trade law, which addresses intellectual property.