Archie Battersbee has died in hospital after weeks of legal battles.
The 12-year-old had been in a coma since he was found unconscious by his mother Hollie Dance in April and was being kept alive by a combination of medical interventions, including ventilation and drug treatments.
Speaking outside the Royal London Hospital in Whitechapel, east London, Ms Dance said her “beautiful little boy” died at 12.15pm on Saturday.
Archie’s parents had fought a long-running legal battle over the withdrawal of treatment and in recent days made bids to the High Court, Court of Appeal and European Court of Human Rights to have him transferred to a hospice to die.
Announcing her son’s death to the media, Ms Dance, of Southend, Essex, said “he fought right until the very end”.
Speaking through tears, she said: “Can I just say, I’m the proudest mum in the world.
“He was such a beautiful little boy and he fought right until the very end, and I am so proud to be his mum.”
In an interview with Sky News, recorded on Friday, Ms Dance said she was “pretty broken” and that the day had been “absolutely awful”.
Breaking down, she said: “The last however many weeks since April 7th, I don’t think there’s been a day that hasn’t been awful really.”
Ms Dance added: “It’s been really hard. Despite the hard strong face and appearance obviously in front of the cameras up until now, I’ve been pretty broken.”
She said the hospital had made it clear there were no more options and that life support would be withdrawn at 10am on Saturday.
Asked if there was anything more she could do, Ms Dance said: “No. I’ve done everything that I promised my little boy I’d do. And I’ve done it.”
Supporters brought flowers to the hospital on Saturday morning.
Shelley Elias, 43, said she had come to the Royal London Hospital because “I wanted his mum Hollie and the family to know I was thinking of them”.
Mrs Elias, a mother of two from Stepney, east London, who said she vaguely knew Archie’s mother, brought flowers, a card and some candles.
She said: “I did not know what to write because there are no words that will take the pain away.
“I just wanted the mum and her family to know that I am here for them.
“My boy is 12, the same age as Archie, and this just puts things in perspective. When things like this happen, you just think ‘I have nothing to moan about in life’.”
Candles flickered in the shape of the letter “A” and also formed a love heart around a card with Archie’s name in a makeshift tribute at a statue in front of the hospital.
It was created by passers-by who said they wanted to show their support.