Christopher Balding, an expert on the Chinese economy and professor at Fulbright University in Vietnam, also sounded a sceptical note because neither side had conceded very much ground.

“I would still say one had to put the odds of this whole thing blowing up at 50%,” he said, adding that the US rollback was “minimal” and “easy to get out of” if China did not fulfil its side of the bargain on agricultural purchases.

Brad Setser, a former US treasury economist and now a fellow at the Council of Foreign Relations thinktank in New York, said an impasse had been reached amid a growing sense in the US that China does not want a deal within the existing framework.

“China won’t get a rollback of all tariffs and the US knows China is not going to moderate its economic model,” he says. “A limited deal is recognition that a broad deal is impossible. Both realise that phase one is all they can get.