Ivana Trump -- Donald Trump's first wife and mother of his three eldest children -- died on Thursday at the age of 73, the former president announced.

Ivana Trump "passed away at her home in New York City," Donald Trump wrote on his social media platform Truth Social.

He did not provide a cause of death but the New York Times reported that law enforcement officials were investigating whether she fell down the stairs at her Manhattan apartment.

A spokesperson for the New York Police Department told AFP in an emailed statement that officers responded to a call at her address on the Upper East Side at around 12:40 pm (1740 GMT).

"Upon arrival, officers observed a 73 year-old female unconscious and unresponsive. EMS (emergency medical services) responded to the location and pronounced the victim deceased at the scene," the spokesperson said.

The statement added that "there does not appear to be any criminality" and that the city's medical examiner will determine the cause of death.

Donald Trump, 76, said in his social media post that Ivana Trump "was a wonderful, beautiful, and amazing woman, who led a great and inspirational life."

"Her pride and joy were her three children, Donald Jr., Ivanka and Eric. She was so proud of them, as we were all so proud of her. Rest In Peace, Ivana!" he added.

Ivana Trump, a model who grew up under communist rule in the former Czechoslovakia, married Donald Trump, then a budding real estate developer, in 1977.

Their first child, Donald Jr., was born later that year. Ivanka was born in 1981 and Eric followed in 1984.

Ivana Trump at the Cannes Film Festival in May, 2000
Ivana Trump at the Cannes Film Festival in May, 2000 AFP / Jack GUEZ

Eric Trump posted a tribute to his mother, who was also an accomplished skier during her childhood in Eastern Europe, on Instagram Thursday.

"Our mother was an incredible woman -- a force in business, a world-class athlete, a radiant beauty, and caring mother and friend," the post said.

"She will be dearly missed by her mother, her three children and ten grandchildren," he added.

Throughout the '80s, the Trumps were one of New York's highest-profile couples, their extravagant lifestyle exemplifying the flashy excesses of the decade.

Their power and celebrity grew as Donald Trump's property business soared, with Ivana Trump taking on number of key roles in the business.

Their high-profile split, rumored to have been caused in part by Donald Trump's affair with actress Marla Maples, provided juicy content for New York's tabloids.

Donald Trump and Ivana Trump divorced in the early '90s and in 1993 the future president married Maples.

Ivana Trump went on to enjoy a successful business career of her own, developing clothing, jewelry and beauty products and penning a number of books.

Donald Trump's union with Maples lasted until 1999. He married has third and current wife, Melania Trump, in 2005.

Ivana Trump was married four times in her life, once before her marriage to Donald Trump and twice after.