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

In a social media post, the United States Catholic Conference of Bishops wrote that as the cathedral reopens its doors, “local churches in the U.S. are invited to peal their bells in a gesture of unity.

The world got its first glimpse on Friday of the newly renovated Notre-Dame Cathedral in Paris. President Emmanuel Macron of France took viewers on a live televised tour of the cathedral's dazzlingly clean interior and rebuilt roofing,