First lady Melania Trump underwent an embolization procedure Monday to treat a benign kidney condition, the White House announced.

Mrs. Trump was treated at Walter Reed National Military Medical Center and will likely be in the hospital for the rest of the week, according to the first lady’s communications director.

“This morning, First Lady Melania Trump underwent an embolization procedure to treat a benign kidney condition. The procedure was successful and there were no complications,” the communications director, Stephanie Grisham, said in a statement Monday. “Mrs. Trump is at Walter Reed National Military Medical Center and will likely remain there for the duration of the week. The First Lady looks forward to a full recovery so she can continue her work on behalf of children everywhere.”

Grisham told Fox News that the first lady “is doing well. Doing well.” She did not say whether the procedure was previously scheduled, but Vice President Mike Pence said Monday night that the procedure was "long-planned."

As Pence opened a speech in Washington marking 70 years of Israeli independence, he told the audience that the procedure was not an emergency and that he was pleased to report that it was a "success and Melania is already on the mend."

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President Trump visited the first lady at the hospital Monday afternoon. Before departing the White House, Trump tweeted that his wife was in "good spirits."

"Thank you to all of the well-wishers!" Trump added.

A White House official told Fox News that the president spoke with his wife before the procedure, and spoke with her doctor afterwards. Trump declined to speak with reporters when he arrived at the hospital.

The White House made the announcement less than an hour after former Senate Majority Leader Harry Reid's family said the lawmaker underwent cancer surgery earlier Monday. Doctors removed a tumor from his pancreas and the prognosis for his recovery is “good,” according to his family.

MELANIA'S KIDNEY CONDITION, 'EMBOLIZATION PROCEDURE' EXPLAINED

Last week, the first lady, who’s 48, unveiled the “Be Best” campaign, which addresses the well-being of children, social media and opioid abuse.

“We can and should be best at educating our children about the importance of a healthy and balanced life,” the first lady said during a speech in the Rose Garden last week.

Last month, she took the lead in planning the first state dinner of the Trump administration, welcoming French President Emmanuel Macron and his wife, Brigitte, to celebrate nearly 250 years of U.S.-French relations.

Fox News' Serafin Gomez and The Associated Press contributed to this report.