President Donald Trump said his wife Melania will leave hospital in a few days, after receiving medical treatment this week for a kidney condition the White House said is non-cancerous.
"Our great First Lady is doing really well. Will be leaving hospital in 2 or 3 days. Thank you for so much love and support!" Trump tweeted.
The first lady, 48, underwent an "embolisation" procedure at Walter Reed National Military Medical Center outside Washington on Monday morning, her office announced.
The president visited her on Monday evening and tweeted that the procedure was "successful" and that his wife was in "good spirits".
Mrs Trump's spokeswoman had said on Monday that the first lady was likely to remain in hospital for "the duration of the week".
The White House has not offered any additional information about the first lady's condition, citing her privacy.
Vice President Mike Pence, however, described the procedure as "long planned" as he opened a speech in Washington on Monday night.
She was last seen in public on Wednesday at a White House event where she and the president honoured military mothers and spouses for Mother's Day.
She later accompanied the president to Joint Base Andrews in Maryland to welcome home three Americans who had been detained in North Korea.
Two urologists who have no personal knowledge of Mrs Trump's condition said the most likely explanation for the embolisation procedure is a kind of non-cancerous kidney tumour called an angiomyolipoma.
They are not common but tend to occur in middle-aged women and can cause problematic bleeding if they become large enough, said Keith Kowalczyk of MedStar Georgetown University Hospital.
"The treatment of choice" is to cut off the blood supply so the growth shrinks.
Doctors do that with an embolisation, meaning a catheter is snaked into the blood vessels of the kidney to find the right one and block it.
Most of the time, these benign tumours are found when people undergo medical scans for another reason, but sometimes people have pain or other symptoms, Kowalczyk said.
Many times, embolisation patients go home the same day or the next.
The Slovenia-born former model married Trump in 2005. They have a 12-year-old son, Barron.