Dr. Anthony Fauci is the top infectious disease expert in the United States.
On Tuesday he said he considers himself "more a realist than an alarmist" reports CNN.
This comes after President Donald Trump on Sunday labeled him "a little bit of an alarmist".
Trump's comments about Fauci were made even as the coronavirus pandemic worsens.
The White House continues to make a concerted effort to discredit Fauci.
Fauci has become increasingly vocal about concerns over reopening amid a national surge in COVID cases.