The US government has blocked a shipment of tens of thousands of Intel processors that would have been used to upgrade China's supercomputer Tianhe-2.
For the last two months Tianhe-2 has been officially recognised as the world's most powerful supercomputer. Using 80,000 of Intel's Xenon chips, the computer has a computational capacity of around 33 petaflops.
To put that into some perspective, just one petaflop is equal to around one quadrillion calculations per second. The shipment of processors were part of an upgrade program that would have pushed China's computer past 110 petaflops.
According to the BBC, the US Department of Commerce blocked the shipment to China citing concerns that the country was going to use the upgraded computers to research advanced nuclear weapons.
The regulations specifically prohibit the export of any product that could directly aid in the creation, research or fabrication of nuclear weaponry.