China is the world's leading producer of the vital minerals used to make magnets crucial to the auto, electronics and defence industries, and since April it has required licences for certain exports of the materials, hitting global manufacturing sectors.

Rare earths have been a major sticking point in recent trade negotiations between China and the United States, with Washington accusing Beijing of slow-walking export licence approvals.

The new controls -- which kick in immediately -- mean exporters must obtain permission for technologies used for rare-earth mining and smelting, among other processing steps, a Chinese commerce ministry statement said.

They will also apply to technologies used in the "assembly, adjusting, maintenance, repair and upgrading of production lines", it said.

The commerce ministry separately said restrictions would be placed on foreign entities that export related items outside of China.

The controls will require such exporters to obtain a permit prior to making certain shipments, the statement said, adding that applications to overseas military users will not be approved.

"For some time, some overseas organisations and individuals have directly or after processing transferred or provided controlled rare-earth items originating in China... for direct or indirect use in sensitive areas such as military operations," a ministry spokesperson said in a statement.

The practice has caused "significant damage or potential threats to China's national security and interests (and) adversely impacted international peace and stability".

In a 2024 assessment, the United States Geological Survey estimated there were 110 million tonnes of deposits worldwide, including 44 million in China.

A further 22 million tonnes are estimated in Brazil and 21 million in Vietnam, while Russia has 10 million and India seven million tonnes.

Beijing has for decades made the most of its reserves by investing massively in refining operations, often without the strict environmental oversight required in Western countries.

China has also filed a huge number of patents on rare earth production, an obstacle to companies in other countries hoping to launch large-scale processing.

As a result, many firms find it cheaper to ship their ore to China for refining, further reinforcing the world's reliance.

The restrictions imposed by Beijing this year have caused significant disruption in worldwide industries, with some companies facing halts to production as supply of the key minerals dwindles.

Following a tense summit in Beijing in July, European Union chief Ursula von der Leyen said leaders had agreed to an improved mechanism for Chinese exports of rare earths to the bloc.

But a business lobby warned last month that European firms still faced challenges in securing access to the materials.

The European Union and the United States are both trying to boost their own production of rare earths and better recycle what they use to reduce dependence on Beijing.