White House trade adviser Peter Navarro was appointed as the Trump administration's point man to enforce the Defense Production Act on Friday, after President Trump authorized the use of the DPA to direct General Motors to build ventilators for patients affected by the novel coronavirus.Why it matters: America's hospitals, doctors and nurses have urged Trump since last week to use the DPA to ramp up the country's domestic production of medical supplies crucial for health care workers, saying "there will not be enough medical supplies" without it.What they're saying: "Ventec, GM and our supply base have been working around the clock for over a week to meet this urgent need. Our commitment to build Ventec’s high-quality critical care ventilator, VOCSN, has never wavered," General Motors said in a statement on Friday."The partnership between Ventec and GM combines global expertise in manufacturing quality and a joint commitment to safety to give medical professionals and patients access to life-saving technology as rapidly as possible. The entire GM team is proud to support this initiative."Navarro said on Friday he is currently "working with over 10 ventilator companies."Flashback: "As usual with 'this' General Motors, things just never seem to work out. They said they were going to give us 40,000 much needed Ventilators, 'very quickly'. Now they are saying it will only be 6000, in late April, and they want top dollar. Always a mess with Mary B. Invoke 'P,' Trump tweeted earlier on Friday, previewing his decision to invoke the act.The White House deal with General Motors and Ventec Life Systems was originally planned to be announced on Wednesday, but was called off to buy more time for the Federal Emergency Management Agency to assess whether the estimated cost of more than $1 billion was too expensive.Go deeper: Defense Production Act: What you need to know