In a speech to the French nation on Wednesday, Macron called Russia a "threat to France and Europe" and said the French were "legitimately worried" about the United States shifting its position on the Ukraine conflict under US President Donald Trump.

"Every day, he makes some absolutely... contradictory statements" which are "detached from reality", Russian foreign ministry spokeswoman Maria Zakharova said of Macron.

Zakharova compared him to Ole Lukoje, a mythical creature in a Hans Christian Andersen fairytale who holds umbrellas over sleeping children.

"I listened to all this, looked at him and realised who he reminds me of -- the nuclear Ole Lukoje," she said.

Macron said he would launch a debate on extending France's nuclear deterrent to other European nations, following a phone conversation with Friedrich Merz, likely to be Germany's next chancellor, on extending that umbrella of protection.