French President Emmanuel Macron has told workers who revived Paris' iconic, fire-ravaged Notre Dame cathedral, that they "achieved what was thought impossible."

You’ve achieved what was said to be impossible,” the French president told workers at the Paris monument, which will reopen after the 2019 fire.

Paris' Notre-Dame Cathedral will reopen on Dec. 7, five and a half years after a devastating fire destroyed its roof and spire and caused major damage throughout.