Mamoudou Gassama is being hailed a hero

A man has climbed up the outside of a building in Paris to save a child who was hanging from a ledge.

Video of Mamoudou Gassama's amazing rescue went viral on social media, and the 22-year-old will now be made a French citizen.

The migrant - originally from Mali - was walking-by when he leapt into action – pulling himself up to the fourth floor with his bare hands.

In less than a minute he pulled himself from balcony to balcony and grabbed the four-year-old as a neighbour tried to hold the child from an adjoining flat.

The city's mayor said she would support the man's effort to settle in France.

President Emmanuel Macron invited Mr Gassama to the Elysee Palace on Monday to thank him personally.

After the meeting, the French president confirmed Mamoudou will be made a French citizen - and the heroic climber will also be offered a position in the Paris fire service.

French President Emmanuel Macron meets with Mamoudou Gassama, 22, from Mali, at the presidential Elysee Palace in Paris. Picture by: Thibault Camus/AP/Press Association Images