“Khan, who is currently under house arrest, led an extensive international network for the proliferation of nuclear equipment and know-how that provided one stop shopping for countries seeking to develop nuclear weapons,” the State Department said in Washington.

The sanctions comes after several years of governmental review of the activities of the Khan network.

“We believe these sanctions will help prevent future proliferation-related activities by these private entities, provide a warning to other would-be proliferators, and demonstrate our ongoing commitment to use all available tools to address proliferation-related activities,” said the department in a statement on Monday.

The State Department asked countries to remain vigilant to ensure that his network, associates or others seeking to pursue similar proliferation activities, will not become a future source for sensitive nuclear information or equipment.