From thousands of miles away, President Trump predicted to a crowd gathered for a roundtable discussion Monday in Minnesota that the Notre Dame cathedral, now engulfed in flames, "looks like it is burning to the ground". Firefighters are tackling the fire which began around 7pm local time - with the spire collapsing in flames two hours later.
French Deputy Interior Minister Laurent Nunez said hours of cooling would be needed and it's too early to say what caused the fire. The cathedral is now undergoing renovations, and BBC News said that these efforts may have caused the blaze.
The cathedral is "more than a historical monument", according to the translated cathedral website. "The copper statues of the twelve apostles and the symbols of the evangelists are also in poor condition".
Pictures posted on social media showed enormous plumes of smoke billowing into the city's skyline as firefighters rushed to the historic site.
Macron tweeted: "Our Lady of Paris in flames".
Macron, who cancelled an address to the nation that he had been due to give on Monday evening, went to the scene of the blaze.
The Paris prosecutor's office says investigators are treating the blaze that destroyed part of Notre-Dame as an accident for now. "Our hearts are with the citizens of France and the tales of Notre Dame, true and fictional, in prayer that they will endure forever".
The steeple of the landmark Notre-Dame Cathedral collapses as the cathedral is engulfed in flames in central Paris on April 15, 2019.
The mayor of Paris, Anne Hidalgo, described it as a bad fire and urged people to respect the boundaries set up by fire crews.
Firefighters are attending to a large fire at the famous Notre Dame cathedral in Paris, France.
With an distinctive French Gothic style, Notre Dame cathedral took almost 200 years to build. Starting in 1163, during the reign of King Louis VII, construction lasted until 1345.
"All means are being used, except for water-bombing aircraft which, if used, could lead to the collapse of the entire structure of the cathedral".
It was unclear Monday afternoon if anyone has been injured in the blaze.
"A bad fire is underway at Notre-Dame Cathedral in Paris", Mayor Anne Hidalgo said on Twitter.
The mayor says city officials are in touch with Roman Catholic diocese in Paris.