BEDMINSTER, NEW JERSEY (REUTERS, NYTIMES) - US President Donald Trump said that his younger brother, Robert Trump, died on Saturday night (Aug 15), a day after the President visited him in a New York hospital.

"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," Mr Trump said in a statement.

Mr Robert Trump, 72, who was two years younger than the president, was a business executive and real estate developer.

President Trump made an emotional visit to see his ailing brother on Friday at New York-Presbyterian/Weill Cornell Medical Center before going to his golf club at Bedminster, New Jersey, for the weekend.

The President was expected to attend the funeral, an aide said. He has a busy travel schedule in coming days with plans to visit four battleground states as part of his re-election campaign.

The White House did not provide a cause of death. Mr Trump told reporters on Friday that his brother was "having a hard time" with an undisclosed illness.

Mr Robert Trump, who took blood thinners, had suffered recent brain bleeds that began after a recent fall, according to a close friend of the family. He had been in poor health since last month. Over the past few weeks, he had not been able to speak on the phone, according to the family friend.

ABC News had reported that Mr Robert Trump was hospitalised in the intensive care unit at Mount Sinai hospital in New York for more than a week in June.

That same month, Mr Robert Trump won a temporary restraining order against his and the President's niece, Ms Mary Trump, to stop her from publishing a tell-all book that offered an unflattering look of the US President and his family.

A state supreme court judge in Poughkeepsie, New York, later denied a request to stop publication and cancelled the temporary restraining order.

Mr Robert Trump had said the book, Too Much And Never Enough: How My Family Created The World's Most Dangerous Man, would violate a confidentiality agreement tied to the estate of his father, Mr Fred Trump Sr, who died in 1999.

Mr Robert Trump had no children, but he helped raise Christopher Hollister Trump-Retchin, the son of his first wife, Ms Blaine Trump, even giving him his last name. Besides the President, he is survived by his second wife, Ms Ann Marie Pallan, and his sisters, Ms Maryanne Trump Barry and Ms Elizabeth Trump Grau. His brother Fred Trump Jr died in 1981.

As the youngest of five children growing up in the strict Queens household of Mr Fred C. Trump, Mr Robert Trump was shielded from some of the pressure exerted by his disciplinarian father over his older brothers.

He was never groomed to take over the family real estate company and was considered by those who knew him to be the inverse of the brash, self-promotional brother who eventually did.

After graduating from Boston University, he first went to work on Wall Street, instead of immediately joining the family business. But he eventually went to work for his brother as a senior executive at the Trump Organization.

"You could consider him the quietest of Trumps," said Mr Michael D'Antonio, a Trump biographer. "He was glad to stay out of the spotlight."

Mr Jack O'Donnell, a former Trump Organization executive who worked closely with the Trump family, recalled the younger Trump as someone with a natural ease and good humour that his older brother lacked.

"He was dignified, he was quiet, he listened, he was good to work with," Mr O'Donnell said. "He had zero sense of entitlement. Robert was very comfortable being Donald Trump's brother and not being like him."

That was not always an easy gig, and simply being a close family member did nothing to shield him from his brother's stormy rages when he needed someone to blame.

Family friends said that as Mr Donald Trump's star grew, Mr Robert Trump struggled with working for his brother and actively cultivated an image as someone who was the polar opposite of the better-known Trump.

But Mr Donald Trump still faulted Mr Robert Trump, for instance, for the problems with slot machines that plagued the opening of the Taj Mahal casino in Atlantic City, New Jersey, in 1990 and cost him tens of millions of dollars in lost revenue.

Mr Donald Trump had put his brother in charge of the property after a fatal helicopter accident in 1989 killed three Trump Organization executives who had been overseeing it.

But gaming regulators did not allow the casino to open because of a complete lack of financial control of the slot machines. On opening night, only a small section of the casino floor was open, and it was months before the slot machines were fully activated.

In one meeting, O'Donnell recalled, Mr Donald Trump lost his temper and screamed at his brother, telling him that he pinned all of the blame on him. "Robert calmly got up, walked out of the room, and that's the last time I ever saw him," Mr O'Donnell said.

After the blowup, Mr Robert Trump stopped reporting directly to his brother and removed himself from the core of the business, working out of the Brooklyn office and dealing with real estate projects in boroughs outside Manhattan that were in the family's portfolio.

But people who knew him said he was devastated by the fight with Mr Donald Trump, and the rift between them took years to heal. During the years Mr Robert Trump worked in Brooklyn, he would take his father, who at the time had Alzheimer's disease, out for lunch every day at Gargiulo's, an Italian restaurant, a friend recalled.

He reconciled with his brother when Mr Donald Trump decided to run for president, according to a person close to the family. Mr Robert Trump had in recent years been a loyal family spokesman and consigliere since his older brother entered politics. "I support Donald 1,000 per cent," he told the New York Post in 2016. "If he were to need me in any way, I'd be there. Anything I could do to help."

The relationship between the brothers - the older one dominating, the younger having to live with it and submit - was illustrated by Mr Donald Trump in his book, The Art Of The Deal."

In it, he recalled stealing his younger brother's blocks and gluing them together so that he couldn't reclaim them. "That was the end of Robert's blocks," he wrote proudly.

The President's decision to visit Mr Robert Trump in the hospital at the end of his life was different from how he handled news in 1981 that his older brother, Mr Fred Trump Jr., was in poor health.

According to Ms Mary Trump's account, Mr Donald Trump went to the movies the night Mr Fred Trump Jr died. Mr Fred Trump, Sr, the patriarch, also did not visit him.

But Ms Gwenda Blair, a biographer of the Trump family, said that in light of the crack that Ms Mary Trump's memoir has put in the Trump family lore, the President would have had no choice.

"It's very much part of the Trump family legend that they are a tight-knit, loyal group," she said. "That is the family modus operandi. Mary Trump has recently suggested otherwise, but I think as part of the response to that, Donald Trump would have no choice but to go."