Vice President Mike Pence has tested negative for COVID-19 after his press secretary contracted the virus.
Katie Miller is at least the second person in the White House to test positive.
At least three top health officials, including doctor Anthony Fauci, are now in self-quarantine as a precaution.
Monday, President Trump is expected to hold a press conference focusing on COVID-19 testing.
Experts said extensive testing, physical distancing, and contact tracing are essential for safely re-opening the nation's economy.
New York City's Mayor is more than doubling the number of city workers being used as what he calls physical distancing ambassadors to more than 2,000.
''We're going to increase intensely the number of public servants who are out there, educating, providing face coverings, reminding people of the rules, helping people to get it right,” said Mayor Bill De Blasio.
Even with states reopening, experts said by June unemployment could reach 20-percent; levels not seen since the Great Depression.
But White House officials said the administration is considering a number of options, including another round of stimulus checks.