Trade talks between the United States and China ended on Friday without a deal.
Two days of discussions concluded on the same day the US increased tariffs on $200bn (£153bn) of Chinese goods from 10% to 25%.
China is expected to hit back, prompting fears the 10-month trade war between the world’s two largest economies could worsen.
US President Donald Trump has ordered his trade chief Robert Lighthizer to begin the process of imposing tariffs on the $300bn (£230bn) remaining imports from China that have not already been targeted.
But Mr Lighthizer said a final decision has not been made on the new duties.
….into the future will continue. In the meantime, the United States has imposed Tariffs on China, which may or may not be removed depending on what happens with respect to future negotiations!
— Donald J. Trump (@realDonaldTrump) May 10, 2019
Mr Lighthizer, Treasury secretary Steven Mnuchin and Chinese Vice Premier Liu He spent just 90 minutes together in Washington DC on Friday.
But Mr Mnuchin insisted discussions had been “constructive”, telling CNBC that future talks had not yet been scheduled.
Mr Trump, meanwhile, described the talks as “candid and constructive”, adding that they would continue into the future.
His Twitter words prompted a slight recovery in US markets, which had been falling earlier in the day: the Dow Jones Industrial Average rose 114 points, or 0.4% while the Nasdaq edged up six points, or 0.1%, to 7,916.
On the Chinese side, Mr Liu said the talks had gone “fairly well”, according to Bloomberg.
Mr Trump has often described China’s trade practices as “unfair” and has put protectionist policies at the centre of his America First agenda.
He said earlier in the day on Twitter that he was in “absolutely no rush” to reach a deal with the Chinese, adding: “Tariffs will bring in FAR MORE wealth to our country than even a phenomenal deal of the traditional kind.”
The US president has tried to persuade Americans that China will absorb the cost of the tariffs but US businesses are more likely to pass the cost on to consumers.
US corporate lobby group Business Roundtable said it was “deeply concerned” that the tariffs would hurt the US economy and called for a final agreement that would “take tariffs down”.
Britain’s chancellor Philip Hammond said he was “optimistic that, in the end, there will be a deal”.
He added: “Clearly if there was a full-blown trade war between the world’s two largest economies, that would be very serious indeed for growth prospects across the world as a whole, including the UK.
“That would be very dangerous but I am optimistic that we won’t get to that.”
Last year China responded to tariffs with levies on some US goods including pork and soybeans, prompting the US government to earmark up to $12bn to help farmers cope.
Dan Ikenson, trade policy expert at the Cato Institute, told Sky News that Chinese trade practices are a problem “but we should be dealing with it differently on a multi-lateral basis”.
He added: “If China and the US descend into this tit-for-tat trade war, it will affect manufacturers and consumers elsewhere in the world.
“The US is increasingly going to look to allies to have its back – you might see this Cold War mentality play out where the Chinese and US are competing for the hearts and minds of other countries.
“If we end up dividing the globe in half, we’re reducing the scope for economies of scale and for sharing technologies. It’s really going to slow down the growth of the global economy.”