The U.S. has banned the export of high-tech semiconductor equipment to Chinese chipmakers and imposed fresh export controls on chips used in artificial intelligence and super computers.

Under the new measures, U.S. companies selling such equipment to Chinese firms that produce certain DRAMs, NAND Flash memory and logic chips must obtain permission, which in practice amounts to a ban.

The requirement also applies to non-Chinese foreign firms, on which the U.S. government will conduct case-by-case reviews.

For instance, among South Korean firms, Samsung Electronics and SK hynix operate several plants in China. They will also have to undergo a license review in order to receive chip-making equipment. 

The U.S. Commerce Department said in a press release that the updated measures will limit China’s ability to acquire advanced computing chips and develop and maintain supercomputers and advanced semiconductors, saying it is part of efforts to protect U.S. national security and foreign policy interests.