"I extend my sincere admiration to the emergency services who have risked their lives to try to save this important national monument. My thoughts and prayers are with those who worship at the Cathedral and all of France at this difficult time."

Charles, who has expressed strong feelings about protecting traditional architecture, said in a message to Macron: "I realise only too well what a truly special significance the cathedral holds at the heart of your nation; but also for us all outside France it represents one of the greatest architectural achievements of Western Civilisation."

He added: "It is a treasure for all mankind and, as such, to witness its destruction in this most dreadful conflagration is a shattering tragedy, the unbearable pain of which we all share."

Prime Minister May said she had told Macron that Britain stood ready to support France in any way it could with rebuilding.

"President Macron has pledged to rebuild the cathedral and I have conveyed to him that the UK will support this endeavour however we can," she said in a statement.