Mainland authorities have begun an investigation into leading US memory chipmaker Micron Technology, a decision the Foreign Ministry said on Monday was intended to safeguard national security.

The decision was announced late on Friday by China's top cybersecurity regulator, which said in an online notice it would review products sold by Micron over "national security concerns".

Foreign Ministry spokesperson Mao Ning told a regular news briefing on Monday the investigation was a normal measure taken to "conduct network security reviews of internet products that affect or may affect national security".

"Both Chinese companies and foreign companies operating in China must abide by Chinese laws and regulations and must not endanger China's national security," she said.

Reports have said that the Boise, Idaho-based Micron was "cooperating fully" with mainland authorities. (AFP)