Ex-US President Barack heartbroken as former 'First Dog' dies.

The Obamas have shared their heartbreak after the tragic death of their family dog Bo.

Barack and Michelle both posted poignant tributes to the much loved pet, confirming he had died today after a battle with cancer.

They said the family had lost a "best friend" and said they would miss him dearly.

Obama posted a series of tweets saying: "Today our family lost a true friend and loyal companion.

"For more than a decade, Bo was a constant, gentle presence in our lives—happy to see us on our good days, our bad days, and everyday in between.

"He tolerated all the fuss that came with being in the White House, had a big bark but no bite, loved to jump in the pool in the summer, was unflappable with children, lived for scraps around the dinner table, and had great hair.

"He was exactly what we needed and more than we ever expected. We will miss him dearly."

Michelle Obama shared a heartfelt statement which began: "This afternoon was a difficult one for our family.

"We said goodbye to our best friend—Bo—after a battle with cancer."

Barack Obama with their dog Bo. (Courtesy)

Michelle explained that on their campaign trail in 2008, they promised their two daughters they would get a puppy after the election.

At the time, Bo was supposed to be a companion for the girls, she said.

But the family had no idea how much he would come to mean to them all.

She described him as a comforting presence in their lives for more than a decade.

He would greet the girls with a wag when they returned from school and was there when she and Barack needed a break.

Michelle also shared a poignant tribute to Bo. (Courtesy)

She said that during the pandemic Bo was happy as he had everyone together again.

'"All his people were under one roof again—just like the day we got him,' Michelle wrote.

"I will always be grateful that Bo and the girls got to spend so much time together at the end.

"As a family, we will miss Bo dearly. But we are thankful that he lived such a joyful life full of snuggles, games of fetch, and evenings spent lying on the couch."

She ended her statement signed with: "Please hug the furry members of your family a little closer tonight—and give them a belly rub from us."