"He was my best friend." Donald Trump's younger brother Robert Trump has passed away.

Robert Trump, the younger brother of the US President Donald Trump, has passed away at the age of 71.

He died on Saturday night in a New York hospital, one day after the president made a visit to see him on Friday. The cause of Robert Trump's death has not yet been released by authorities. 

"It is with heavy heart I share that my wonderful brother, Robert, peacefully passed away tonight. He was not just my brother, he was my best friend. He will be greatly missed, but we will meet again. His memory will live on in my heart forever. Robert, I love you. Rest in peace," Donald Trump said in a statement.

Donald Trump hugs his brother Robert Trump after delivering his acceptance speech in New York on November 9, 2016. 

Robert Trump, who was two years younger than the president, was a business executive and real estate developer.

After visiting his brother on Friday, Trump went to his golf club at Bedminster, New Jersey, for the weekend.

Donald Trump once described his younger brother Robert as “much quieter and easygoing than I am,” and “the only guy in my life whom I ever call ‘honey.’”

The president is expected to attend the funeral, an aide said.

Watch: Fox News reports Robert Trump's death. Post continues below. 

Robert Trump recently made headlines for spearheading the failed lawsuit to the halt the publication of his niece Mary Trump's tell-all book about the US President, called How My Family Created the World's Most Dangerous Man.

Two of Donald Trump's children paid tribute to their 72-year-old uncle on Twitter. 

Uncle Robert, we love you. You are in our hearts and prayers, always.

— Ivanka Trump (@IvankaTrump) August 16, 2020

Robert Trump was an incredible man - strong, kind and loyal to the core. Anyone who encountered him felt his warmth immediately. He will be deeply missed by our entire family.

— Eric Trump (@EricTrump) August 16, 2020

"Robert Trump was an incredible man - strong, kind and loyal to the core," Eric Trump said. "Anyone who encountered him felt his warmth immediately. He will be deeply missed by our entire family."

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