The ruling came after the UN Committee on the Rights of Persons with Disabilities asked for treatment of Archie Battersbee to be continued so it could examine the case.
A UK court has ruled to end life support for a 12-year-old boy despite opposition from his parents and a last-minute intervention by the United Nations.
The Court of Appeal in London decided on Monday that doctors can switch off life support for Archie Battersbee from 1100 GMT on Tuesday.
Archie had been due to have his life support at the Royal London Hospital ended Monday afternoon after his parents failed in a domestic legal bid to halt the move.
As a last resort, Archie's parents applied to the United Nations and the UN Committee on the Rights of Persons with Disabilities.
The UN committee requested on Friday that his treatment be continued while Archie's case was under consideration.
The UK government then asked the Court of Appeal to "urgently consider" his case Monday afternoon. An appeal court judge argued the UN request was not enforceable but granted a delay until 12 noon tomorrow.
The Court of Appeal is a High Court based at the Royal Courts of Justice in London.
Archie's parents can still ask the UK Supreme Court if it will hear the case. If it agrees, the deadline would likely be extended again.
'It's so traumatic'
Archie's mother, Hollie Dance, discovered him unconscious at home in April with signs he had placed a ligature over his head, possibly after taking part in an online asphyxiation challenge.
UK courts earlier found that ending life-preserving treatment for Archie was in his best interests as doctors believe he is brain-stem dead.
In an interview with Sky News, Dance condemned what she called the "choreographed execution of my son".
"It's so traumatic: to just be dragged through courts, no empathy, no compassion," she said.
The case is the latest in the UK that has pitted the judgment of doctors against the wishes of families.
In several cases, including this one, the families have been backed by a campaign organisation, the Christian Legal Centre. The centre's chief executive, Andrea Williams, tweeted that the case "goes right to the heart of protections at end of life".
Under British law, it is common for courts to intervene when parents and doctors disagree on the treatment of a child. In such cases, the rights of the child take primacy over the parents’ right to decide what’s best for their offspring.