TOKYO—Japan is studying restrictions on Chinese telecommunications-equipment companies Huawei Technologies Co. and ZTE Corp. ZTCOY -3.64% as U.S. fears of  Beijing prod allies to follow suit.

U.S. officials have been arguing that using equipment from the two companies in network infrastructure constitutes a security risk. Australia last week banned both Chinese companies from its next-generation mobile network. A July study by the U.K. governmentsaid it found “shortcomings” in Huawei’s engineering processes that exposed new risks.

Officials responsible for cybersecurity in the Japanese government’s Cabinet Office said they have begun to study whether tighter regulations are needed to reduce the risk of infiltration through imported equipment, including equipment made by the Chinese companies. One of the officials said Japan was aware of other countries’ moves but would make a decision about regulation on its own.