Washington's announcement of a visa ban for Chinese officials linked to mass detentions of Muslims in Xinjiang - on the eve of a new round of trade talks - is a now-familiar tactic of raising the pressure in the hope that Beijing will make concessions.

But applying such leverage only reduces the already slim chance of any breakthrough when Vice-Premier Liu He meets his US trade counterparts - Treasury Secretary Steven Mnuchin and Trade Representative Robert Lighthizer - today, Chinese experts said.