In a deal with Swiss energy company Axpo, Kazatomprom said they had signed "the first ever contract for the supply of Kazakh natural uranium concentrates for the energy needs of Switzerland's Beznau and Leibstadt nuclear power plants".

An Axpo representative said the deal would help "ensure stable energy supply for Switzerland and contributes to global decarbonisation efforts" to limit greenhouse gas emissions that contribute to global warming.

No details were given about the volume of deliveries.

In December, the Swiss federal government signalled its intention to change the law to allow the construction of new nuclear power plants in the Alpine nation, banned since 2018.

The government said the move was required because of Switzerland's population growth and its target of net zero carbon emissions by 2050.

But the authorities also said there were also fears of electricity shortages due to the fall in Russian gas deliveries, after Europe imposed sanctions on Moscow following its invasion of Ukraine.

Four ageing nuclear reactors produce around 29 percent of Switzerland's electricity supply and in winter it has to import energy from elsewhere.

Kazakhstan, a central Asian country bordering Russia and China, is by far the world's largest uranium producer with more than 40 percent of global extraction.

Despite its vast natural resources, Kazakhstan suffers from chronic energy shortages and is due to build a nuclear power plant on the shores of Lake Balkhash in the south.

That project has piqued the interest of China, Russia, France and South Korea.