Trump flew to Walter Reed National Military Medical Center in Bethesda, Md., and arrived shortly after 4 p.m. He remained at the hospital for about 80 minutes.
"Melania is in the hospital doing really well," Trump said earlier Tuesday during remarks at the National Peace Officers' Memorial Service. "She's watching us right now and I want to thank the incredible doctors. Walter Reed medical center, they did a fantastic job, so thank you. She sends her love."
Trump also sent a tweet thanking his Twitter followers "for so much love and support!"
The first lady's communications director, Stephanie Grisham, said in a tweet Monday night that Melania was in "good spirits and doing really well."
The president said Melania Trump would leave the hospital in two to three days.
The first lady is recovering at Walter Reed National Military Medical Center, after undergoing an embolization procedure, which starves the blood supply to the affected area.
"The procedure was successful and there were no complications," Grisham said. "The first lady looks forward to a full recovery so she can continue her work on behalf of children everywhere."
Trump also visited the first lady Monday afternoon after her treatment.
Melania Trump is the first U.S. first lady to undergo a serious medical procedure while in the White House since Nancy Reagan had a mastectomy in October 1987. In April 1977, Rosalynn Carter underwent surgery to remove a benign lump from her breast and in September 1974, shortly after Betty Ford became first lady, she was diagnosed with breast cancer and underwent a mastectomy.
Last week, the first lady launched an initiative known as "Be Best," which will center on three pillars including well-being, social media use and opioid abuse.