WASHINGTON, July 27 : The Pentagon official tasked with building a domestic drone industry said on Monday the United States is still in the earliest, hardest phase of that effort, acknowledging output remains a fraction of Ukraine's production even as the government tightens rules requiring drones be built with American-made parts.Travis Metz, deputy director and chief operating officer of the Defense Innovation Unit who has run the Pentagon's Drone Dominance Program since last fall, said in an interview that Ukraine will produce between six and seven million small first-person-view attack drones this year, or roughly 500,000 a month.By comparison, the Pentagon's $1.1 billion program will have ordered just under 200,000 drones cumulatively by February. "It's much harder to get from zero to 200,000" than it will be to scale up further once a domestic capacity to build many more drones exists, Metz said.But the Pentagon just made a big surge in drone building much tougher when it instituted rules that military drones must be made with U.S. parts. A revised supply chain framework released July 23 adds language stating the government's ultimate goal is "a wholly domestic" small unmanned aircraft system supply chain.