The Pentagon is working on a software "do not buy" list to block vendors who use code originating from Russia and China, a top Defense Department acquisitions official said on Friday.

Ellen Lord, the undersecretary of defense for acquisition and sustainment, told reporters the Pentagon had been working for six months on a "do not buy" list of software vendors. The list is meant to help the Department of Defense's acquisitions staff and industry partners avoid buying problematic code for the Pentagon and suppliers.

"What we are doing is making sure that we do not buy software that has Russian or Chinese provenance, for instance, and quite often that's difficult to tell at first glance because of holding companies," she told reporters in a conference room near her Pentagon office.