Trump on Wednesday said he was signing the new order "just in case" his administration needed its powers to expand the supply of resources to deal with the COVID-19 outbreak.
Speaking to reporters in Washington on Friday, Trump said he was using the act.
"I invoked the Defense Production Act and last night, we put it into gear," Trump said.
"We need certain equipment that the states are unable to get by themselves. So we're invoking it to use the powers of the federal government to get things that they need."
Two items that the government is going to send to states: masks and ventilators.
The federal government has millions of masks and the act will allow it to distribute masks directly to the states.
"The act is very good for things like this," Trump said.
Millions of additional masks will be needed during the outbreak, officials said earlier in the week.
The act also gives the president the power to authorize loan guarantees and order the take over or enhancement of private industrial facilities.
More than two dozen senators urged Trump earlier in the month to invoke the Korea War-era program to increase production of masks, ventilators, and respirators. Expanding hospital capacity could also be done, the lawmakers said.
The 1950 act "authorizes the president to strengthen capacity and supply in extraordinary circumstances,” Senate Minority Leader Chuck Schumer (D-N.Y.) said on Wednesday.
“It’s used in times of war, but we must mobilize as if it is a time of war when it comes to hospitals, beds, supplies, equipment.”
Governors on a call with Trump Thursday asked about how the Trump administration would use the act, with Massachusetts Gov. Charlie Baker asking about how the implementation of the act would be used to generate personal protective equipment, which includes masks and gloves.
Maryland Gov. Larry Hogan, chairman of the National Governors Association, told the president that states want to be involved in helping hammer out how the act can be used, especially with industries in certain states.
Two hundred and sixteen people in America have died from the new illness.