What just happened? The US government threw Huawei’s business into disarray when it added the company to an Entity List earlier this year. Now, the Trump administration has blacklisted five more Chinese firms, all of which are involved in the supercomputer industry.

The US says the companies were added to the list, which prevents them from doing business with American organizations without a license, due to concerns over the military applications of the supercomputers they develop.

Hygon, Chengdu Haiguang Integrated Circuit, Chengdu Haiguang Microelectronics Technology, Sugon, and Wuxi Jiangnan Institute of Computing Technology were blacklisted on Friday.

While the US has the two fastest supercomputers in the world, China has 219 entries in the TOP500 compared to America’s 116. Sugon, one of the blacklisted firms, is the third-highest vendor in the TOP500 with 63 machines. It's one of many companies that rely on American technology—Intel’s chips appear in 95.6 percent of the top 500 supercomputer systems, while Nvidia’s GPUs are in 125 machines.

Hygon, you may recall, produces Dhyana processors, which are said to be virtually identical to AMD’s EPYC CPUs—a result of the US firm’s deal with a Chinese consortium in 2016 that saw it license its x86 and SoC IP for developing chips, which would be sold exclusively in China. Earlier this month, AMD said it would not be extending the agreement, a move that many speculated was related to the trade war. AMD has confirmed it will comply with the new trade restrictions.

The move comes ahead of the G20 summit in Japan, where Presidents Trump and Xi Jinping are set to meet in an attempt to address the trade dispute between the two countries.