China has dramatically expanded its rare earths export controls, adding five new elements and extra scrutiny for semiconductor users as Beijing tightens control over the sector ahead of talks between leaders Donald Trump and Xi Jinping.

The world's largest rare earths producer also added dozens of pieces of refining technology to its control list and announced rules that will require compliance from foreign rare earth producers who use Chinese materials.

The Ministry of Commerce's announcements follow US politicians' calls on Tuesday for broader bans on the export of chipmaking equipment to China.

They expand controls that Beijing announced in April that caused shortages around the world, before a series of deals with Europe and the US eased the supply crunch.

"The White House and rele

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