WASHINGTON (Reuters) – The head of the U.S. Food and Drug Administration said on Saturday that materials for 2.1 million coronavirus tests will have been shipped to non-public U.S. labs by Monday, as the Trump administration aims to counter criticism that its response to the disease has been sluggish.

Stephen Hahn, the FDA commissioner, told reporters at the White House that manufacturers have told the agency they believe that by the end of next week they could scale up to a capacity of 4 million additional tests.

(Reporting by Timothy Gardner and Diane Bartz; Editing by Leslie Adler)