The U.S. government may expand its power to stop foreign shipments of products containing U.S. technology to China's Huawei amid frustration that the blacklisting of the company has failed to cut off supplies to the world's largest telecommunications equipment-maker, two sources said.

The U.S. Commerce Department in May placed Huawei Technologies on a trade blacklist, citing national security concerns. Putting Huawei on the entity list, as it is known, allowed the U.S. government to restrict sales of American-made goods to the company, plus some limited items made abroad that contain U.S. technology.

But under current regulations, key foreign supply chains remain beyond the reach of U.S. authorities.