The parents of Charlie Gard want to appeal after a judge ruled that doctors could withdraw life-support treatment for their sick baby against their wishes, their lawyer has said.
Specialists at Great Ormond Street Hospital in London say eight-month-old Charlie, who suffers from a rare genetic condition and has brain damage, should move to a palliative care regime.
But his parents, postman Chris Gard and Connie Yates, from Bedfont, west London, who are both in their early 30s, want to be allowed to take him to a hospital in the US for treatment.
Solicitor Laura Hobey-Hamsher said outside court that the couple would have three weeks to launch a challenge.
She said: "Connie and Chris are devastated by today's decision."
She added: "They are struggling to understand why the court has not at least given Charlie the chance of treatment in America."
Mr Justice Francis ruled with the "heaviest of hearts" that life-support treatment should stop after analysing evidence at a hearing in the Family Division of the High Court and visiting Charlie in hospital.
Charlie, who was born on August 4, 2016, has a form of mitochondrial disease, a condition which causes progressive muscle weakness and brain damage.
His parents launched an appeal on the GoFundMe website two months ago, saying they needed £1.2 million to fund the US treatment.
They reached their target on Sunday after more than 80,000 people donated.
After hearing the decision, barrister Pravin Fernando told the judge that the couple wanted to challenge his ruling in the Court of Appeal.
Lawyers representing Great Ormond Street said treatment would continue until appeal decisions had been made.