Donald Trump appeared to back the yellow vest protesters in a provocative message to Emmanuel Macron, the French president, claiming that the Paris climate change agreement had triggered the unrest.
The US president also claimed protesters were chanting his name on the streets of the French capital, as his rift with Mr Macron continued to deepen.
As demonstrators were clashing with police in Paris and protests were being held across France on Saturday, Mr Trump said: "The Paris Agreement isn’t working out so well for Paris. Protests and riots all over France. People do not want to pay large sums of money, much to third world countries (that are questionably run), in order to maybe protect the environment. Chanting ‘We Want Trump!’ Love France."
Sunday Telegraph reporters, placed across the city, heard no such chants.
He later tweeted that the protests were "very sad" and reiterated his call for Mr Macron to pull out of the Paris climate change deal, and agree to lower taxes.
He did not specify how he believed the agreement and taxes were linked.
The provocative intervention comes at a difficult moment for Mr Macron, who has taken pride in his ability to "manage" Mr Trump.
Last year he invited him to Paris for the Bastille Day celebrations, rolling out the red carpet and leaving the US leader so impressed he wanted his own military parade in Washington DC.
Mr Trump then returned the honour, inviting Mr Macron and his wife Brigitte in April to the one and only state dinner he has held so far.
The two men cemented their friendship by planting a tree on the White House lawn.
But in recent months the relationship has soured.
Mr Macron used his Armistice Day speech to deliver a pointed rebuke to Mr Trump’s nationalism, and Mr Trump hit back, mocking his French counterpart and saying he should try to "make France great again".
Mr Macron responded by saying that France would not be pushed around by the United States.