While tariffs have been placed on the companies wanting to import goods from abroad, China has also imposed export controls on 25 rare metals.

Some of the metals are key components for many electrical products and military equipment.

China has mastered the ability to refine such metals, and produced almost 90% of global refined output.

The restricted list includes tungsten, which is difficult to source and a crucial material for the aerospace industry.

While there are restrictions on exports, Mr Evans-Pritchard of Capital Economics, said it was notable that the critical metals China imports from the US, which are used to make high-end chips, semiconductor machinery, pharmaceuticals and aerospace equipment were not targeted in any measures.

The experience of previous rounds of restrictions suggests exports will drop sharply as companies scramble to get licences, a process that takes several weeks.

When it comes to the impact of the restrictions, it appears the US has a plan. On Monday, Trump said he wanted Ukraine to guarantee the supply of more rare earth metals in exchange for $300bn of support in its fight against Russia.