The Tianhe-2 uses 80,000 Intel Xeon chips to generate a computational capacity of more than 33 petaflops and is, according to the Top 500, an organisation that monitors supercomputers, currently the world's most powerful machine.
The machine was due to undergo a series of upgrades this year in order to boost its abilities to over 110 petaflops but the upgrade was dependent on new Intel Xeon chips. The chipmaker informed US authorities of its involvement with the upgrade programme and was told to apply for an export licence.
The US Department of Commerce said it refused Intel's application to export the chips for Tianhe-2 and three other Chinese supercomputers because the machines were being used for "nuclear explosive activities" and as a result were deemed to be "acting contrary to the national security or foreign policy interests of the United States".
In response Intel said: "Intel complied with the notification and applied for the licence, which was denied. We are in compliance with the US law."
China is now believed to be accelerating its own home-grown chipmaking efforts to boost the power of the four supercomputers and complete the upgrade programme.
In separate news Intel has signed a $200million deal with the US government to build a massive supercomputer at one of its national laboratories.
