The U.S. Commerce Department is expected to extend a reprieve given to Huawei Technologies that permits the Chinese firm to buy supplies from U.S. companies so that it can service existing customers, two sources familiar with the situation said.

The "temporary general license" will be extended for Huawei for 90 days, the sources said.

Commerce initially allowed Huawei to purchase some American-made goods in May shortly after blacklisting the company in a move aimed at minimizing disruption for its customers, many of which operate networks in rural America.