Nick Cannon has announced that his five-month-old son Zen has died after being diagnosed with a brain tumour.

The America's Got Talent and Masked Singer US host confirmed the news during The Nick Cannon Show on Tuesday.

He called the episode a "celebration of life" for his late son, who died last weekend.

Cannon recalled the moment he and his partner, model Alyssa Scott, were told that Zen had hydrocephalus - a build-up of fluid in the brain.

Zen underwent surgery, Cannon explained, but suffered "an interesting turn" during Thanksgiving [25 November] and the "process sped up".

Before his son died, Cannon said they took him to the ocean and held his hand for a final time.

"You can't heal until you feel," he told the audience about such loss, drawing loud cheers. While friends, fans and others shared supportive messages online.

"We have the word widower for when a husband or wife loses their spouse," said one fan on Twitter. "We have the word orphan for when a child loses their parent. But we have no word for when a parent loses their child."

"I am praying for you brother, this is such heart-breaking news," added another. "You all will get through this, together. Just know you aren't alone. You have people who loves you and will hold your hand through this process."

Cannon has seven children, including Zen, the eldest two from his marriage to ex wife and pop superstar Mariah Carey.