Amalija Knavs, the mother of former first lady Melania Trump, has died. She was 78.

Trump announced the death late Tuesday without disclosing the cause.

"It is with deep sadness that I announce the passing of my beloved mother, Amalija," Trump wrote on X, the platform formerly known as Twitter. "Amalija Knavs was a strong woman who always carried herself with grace, warmth, and dignity. She was entirely devoted to her husband, daughters, grandson, and son-in-law. We will miss her beyond measure and continue to honor and love her legacy."

Donald Trump said at a New Year's Eve celebration at his Mar-a-Lago estate in Palm Beach, Florida, that his mother-in-law was "very ill" and his wife was with her at a hospital in Miami.

"It's a tough one, very tough one," he said of the situation.

During the Trump presidency, the first lady's mother lived in New York along with her father, Viktor Knavs, and occasionally appeared at the White House. Amalija Knavs was at a 2018 ceremony where the first lady debuted her "Be Best" public awareness campaign to help children.

"This is a very sad night for the entire Trump family!!!" Trump wrote on his social media site, Truth Social. "Melania's great and beautiful mother, Amalija, has just gone to a beautiful place in the sky. She was an incredible woman, and will be missed far beyond words!"

Melania Trump sponsored her parents' immigration to the United States, and they took the oath of office to become citizens at a New York City courthouse in 2018, while Trump was president. The Slovenian immigrants, a former car dealer and a textile factory worker, had been living in the U.S. as permanent residents.

Their lawyer said at the time that they applied for citizenship on their own and didn't get any special treatment.

The Knavses raised Melania, born Melanija, in the rural industrial town of Sevnica while Slovenia was under Communist rule.

She attended high school in the Slovenian capital, Ljubljana, and changed her name to Melania Knauss when she started modeling.

She settled in New York in 1996 and met Trump two years later. They married in 2005.