US and Chinese officials are making meaningful progress in high level trade talks, US President Donald Trump said today.

His comments will feed optimism about prospects for a deal to cease hostilities.

"Good things are happening at China Trade Talk Meeting. Warmer feelings than in recent past, more like the Old Days," Trump said on Twitter shortly after officials resumed negotiations for a second day.

"All would like to see something significant happen!"

Top US and Chinese negotiators wrapped up a first day of trade talks in more than two months yesterday.

Business groups expressed optimism the two sides might be able to ease a 15-month trade war and delay a US tariff hike scheduled for next week. 

US Treasury Secretary Steven Mnuchin and US Trade Representative Robert Lighthizer met with Vice Premier Liu He and other senior Chinese officials for about seven hours at the USTR's headquarters near the White House. 

A White House official said talks had gone very well, "probably better than expected." 

A smiling Liu waved to reporters before departing the USTR in a black Cadillac, without answering questions. The two sides were due to meet for a final day today. 

Negotiators could agree to low-level "early harvest" agreements on issues such as currencies and copyright protections, despite increased irritants between the world's two largest economies, a US Chamber of Commerce official briefed by both sides said yesterday. 

Myron Brilliant, the Chamber's head of international affairs, said that negotiators were "trying to find a path towards the bigger deal" with progress on market access and less controversial intellectual property and other issues.

Donald Trump launched the trade war against China with demands for sweeping structural reforms, but Beijing has indicated it is not willing to fundamentally change the way it controls China's economy. 

Asked by reporters whether he was prepared to accept a "smaller deal," Trump did not answer and walked away. 

Previously, the president said he did not want to have a more limited deal, preferring to hold out for one that was broad in scope. 

Steady escalations of the tit-for-tat tariffs on Chinese and US goods in recent months have hit financial markets and stoked fears of a global recession.

The mood surrounding the talks had soured earlier this week when the US government blacklisted 28 Chinese public security bureaus, technology and surveillance firms, including video surveillance gear maker Hikvision, over allegations of abuses of Muslim minorities in China.

Washington also restricted visas for certain Chinese officials over the same issue and Beijing was said to be planning to tighten visa restrictions for some US nationals. 

But Chinese officials indicated more willingness to negotiate and avoid further escalation, according to Chinese state media reports. 

"The Chinese side came with great sincerity, willing to cooperate with the US on the trade balance, market access and investor protection," Xinhua quoted Liu as saying yesterday. 

The two sides have been at loggerheads over US demands that China improve protections of American intellectual property, end cyber theft and the forced transfer of technology to Chinese firms, curb industrial subsidies and increase US companies' access to largely closed Chinese markets.

The discussions were not expected to address the most contentious issues in the talks, leaving them for a possible future negotiations.