"I know the tremendous pain of losing a loved one — and I know how important family is in moments like these," Joe Biden said
Trump, Biden
Donald Trump and Joe Biden
| Credit: Leon Neal/Getty Images; MediaPunch/Shutterstock

Joe Biden is offering his condolences to Donald Trump after the president's younger brother, Robert Trump, died on Saturday at age 71.

"Mr. President, Jill and I are sad to learn of your younger brother Robert's passing," Biden, 77, wrote in a tweet from him and his wife, Dr. Jill Biden.

"I know the tremendous pain of losing a loved one — and I know how important family is in moments like these. I hope you know that our prayers are with you all," said Biden, whose son Beau Biden died in 2015 from brain cancer at the age of 46.

Robert died on Saturday at 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," the president said in a Saturday evening statement obtained by PEOPLE.

In response to Biden's tweet, his running mate, Sen. Kamala Harris, also expressed her condolences and offered "prayers" to the Trump family.

"Doug and I join the Biden family in sending our deepest condolences and prayers to the entire Trump family during this difficult time. Losing a loved one is never easy but know that we are thinking of you," Harris posted on Twitter.

During an appearance on CBS News' Face the Nation, the president's son-in-law, Jared Kushner, responded to the news of Robert's death.

"The president loved his brother very much. He was able to see him the day before yesterday," Kushner said. "His brother was very proud of him. And obviously a very tough moment for the president, but he is looking forward to continuing to do great things and make his brother proud."

Robert died after a summer of ill health, including a sudden hospitalization only a few weeks before the president is set to give his acceptance speech to the Republican National Convention.

The president visited his brother in New York City on Friday, one day before his death. Robert suffered brain bleeds after a fall, The New York Times reported.

A cause of death has not been made public.

Robert Trump and Donald Trump
From left: Robert Trump hugs his brother Donald Trump after the president delivered his acceptance speech in the early morning hours of Nov. 9, 2016, in New York City
| Credit: Chip Somodevilla/Getty

After news of Robert's passing, three of the president's children — Donald Trump Jr., Eric Trump and Ivanka Trump — reacted to the news on social media.

"Uncle Rob, we love you and we will miss you. R.I.P," Donald Jr. wrote, as Eric shared, "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."

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