The US trade war with China has a major sticking point: rare earths minerals. Last month, President Donald Trump said the United States needed Greenland “very badly,” renewing his threat to annex the Danish territory.

US negotiators will aim to restore the flow of critical minerals when they meet their Chinese counterparts for a new round of trade negotiations Monday in London, a top economic aide to President Donald Trump said.

China has agreed to fast-track approvals for the shipment of rare earth minerals to the United States and some European Union nations.