When US President Donald Trump in early April hit back with extremely high import tariffs against China, among others, Beijing responded with its own tariffs and by strangling the export of vital minerals.
These are needed not least for the production of smart phones, chips and other electronics by American companies.
After a long series of mutual accusations, the world's two largest economies agreed at negotiations in Geneva in May to put the raised import tariffs on hold for 90 days to give room for further talks.
However, Beijing and Washington have recently accused each other of breaking the agreement in Switzerland.
During the second round of negotiations, which began in London on Monday, the US has set its sights on getting China to release significantly more of the minerals, according to White House economic advisor Kevin Hassett.
Export of critical minerals has been released at a pace that is, you know, higher than it was but not as high as we think we agreed on in Geneva, he says in an interview with CBS's program "Face The Nation".
Hassett says that the US wants the minerals to flow as freely as they did before April.
Trump has, after a phone call with President Xi Jinping on Thursday, said that China should increase the export.
I am very confident that this agreement will soon be in place, Hassett says to CBS.
