TRADE talks between China and the United States in London set to begin tomorrow are expected to take up a series of fresh disputes that have hit an already rocky road, threatening a fragile truce over tariffs.

Both sides agreed in Geneva last month to a 90-day suspension of most of the 100 per cent-plus tariffs they had imposed on each other in an escalating trade war that had sparked fears of recession.

Since then, China and the US have exchanged angry words over advanced semiconductors that power artificial intelligence, “rare earths” that are vital to car makers and other industries, and visas for Chinese students at US universities.

President Donald Trump spoke at length with Chinese leader Xi Jinping by phone last Thursday in an attempt to put relations back on track.

Mr Trump announced on social media the next day that trade talks would be held on Monday in London.

The latest frictions began just a day after the May 12 announcement of the Geneva agreement to “pause” tariffs for 90 days.

The US Commerce Department issued guidance saying that the use of Ascend AI chips from Huawei, a leading Chinese tech company, could violate US export controls. It claims the chips were developed with US technology despite restrictions on its export to China.

One of China’s biggest complaints in recent years has been over US moves to limit the access of Chinese companies to technology, and in particular to equipment and processes needed to produce the most advanced semiconductors.

“The Chinese side urges the US side to immediately correct its erroneous practices,” a Commerce Ministry spokesperson said.

US Commerce Secretary Howard Lutnick wasn’t in Geneva but will join the talks in London. Analysts say that suggests at least a willingness on the US side to hear out China’s concerns on export controls.

One area where China holds the upper hand is in the mining and processing of rare earths. They are crucial for not only autos but also a range of other products from robots to military equipment.

The Chinese government started requiring producers to obtain a license to export seven rare earth elements in April. Resulting shortages sent car makers worldwide into a spin. As stockpiles ran down, some worried they would have to halt production.

The Chinese government indicated on Saturday that it is addressing the concerns over access to rare earth elements.

A Commerce Ministry statement said that it had granted some approvals and “will continue to strengthen the approval of applications that comply with regulations.”