He tweeted, "Not that this will deter the conspiracy theorists, but I saw the First Lady walking with her aides in the West Wing yesterday afternoon".
The White House said in a statement on Tuesday that Melania is "doing great" and is returning to work: "She has had several meetings ... and will continue to do so this week".
Trump, 48, has not been seen in public since May 10, four days before she underwent the procedure at Walter Reed National Military Medical Center on May 14.
Earlier this month, the first lady had launched her long-awaited signature initiative, "Be Best", which she described as a wide-ranging effort aimed at helping children.
A week after the first lady announced "Be Best", she was in the hospital.
Browns' Damarious Randall amazed by record-setting post, retweeted nearly 900000 times
Kyrie Irving (L) in the Nike Kyrie 3 and Stephen Curry in the Under Armour Curry 4 during the 2017 NBA Finals . It's a small city with a fan base that wants its athletes to support the hometown team.
Grisham said the disappearance from the public eye isn't unusual. Some doctors familiar with the procedure but not involved in her care said people treated with embolization typically are sent home the same day or the next. "Right there. She's doing great".
"We must break down barriers to youth sports participation and empower each child to reach his or her full potential through sport and play", Ivanka Trump said. "Reporters turned to look at the spot he indicated, but there was no sign of the First Lady".
The first lady has tweeted a few times in the past two weeks, including a thank-you to the hospital staff and a recognition of Medal of Honor recipient Britt Slabinski, a Navy SEAL who oversaw a daring rescue mission in Afghanistan.
Former football star Herschel Walker is mobbed as he arrives Wednesday for the White House field day on the South Lawn.
Meanwhile, according to CNN, the first lady hasn't appeared in public for 20 days. After Stephanie shared her boss's tweet, one person jokingly demanded more, writing, "Could we maybe get a video holding today's paper?" A recent picture of Trump with Kim Kardashian on his right accompanied the post.
She's also endured fevered speculation about the state of her marriage after cameras caught her brushing off his extended hand and after she cancelled a foreign trip with him following explosive allegations from a former adult film star that she had a one-night fling with him years ago and was paid to keep quiet about it before the 2016 election.