WASHINGTON—President Trump said he would leave the hospital and return to the White House later Monday, saying he was feeling “really good” despite questions about his condition and after other officials in his inner circle tested positive.

“Don’t be afraid of Covid,” Mr. Trump said in a tweet. “Don’t let it dominate your life. We have developed, under the Trump Administration, some really great drugs & knowledge. I feel better than I did 20 years ago!”

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