They are words likely to bring a look of trepidation to the faces of Prince George's parents.
Prince Harry said yesterday that one of his missions would be to make sure his newborn nephew "has fun".
But with his track record of partying misdemeanours, the Duke and Duchess of Cambridge might feel inclined to ensure Uncle Harry does not exert too great an influence on his replacement as third in line to the throne.
However, if they were in need of reassurance, the Prince, 28, said he would also make sure that his nephew "has a good upbringing" and would "keep him out of harm's way".
He added that he would be happy to babysit for his brother, if the Duke could afford the fee.
The Prince, who met his nephew at Kensington Palace on Wednesday morning, said: "When I saw him he was crying his eyes out, like all babies", and, asked if he had had a cuddle, smiled: "Of course".
He went on: "It's fantastic to have an addition to the family. I only hope my brother knows how expensive my babysitting charges are."
Asked what his mission was as an uncle, he replied: "To make sure he has a good upbringing, to keep him out of harm's way, and make sure he has fun.
The rest of it I leave to theparents."
The Prince said it was too early to say whether Prince George took after any member of the family.
"He is about four days old so I think you can judge that one for yourself. I've no idea."
When he was asked whether Prince William was up to the job of fatherhood, he replied: "Of course he is. Hopefully most people are."
The Prince was speaking at a private viewing of a photographic exhibition in London showcasing the work of his charity Sentebale, which helps vulnerable children in Lesotho, one of the world's poorest countries.
In Gloucestershire yesterday, Prince Charles spoke about the "great moment" he met his grandson, telling a young well-wisher "it's fun to be a grandfather".