Emmanuel Macron has said he will overhaul media law in France this year to fight the spread of "fake news" on social media.
Since he was elected last year, the French President has criticised Russian media in particular, openly accusing TV channel RT of sowing disinformation about him via its website and social media during the presidential election.
"If we want to protect liberal democracies, we must have strong legislation," Mr Macron told a news conference on Wednesday.
Mr Macron said the legislation would concern social media platforms, especially during election periods, and deeply change the role of France's media watchdog CSA.
Websites would have to say who is financing them and the amount of money for sponsored content would be capped, the French president said.
In the case of fake news published during elections, an emergency legal action could allow French authorities to suppress that content or even block access to the website, Mr Macron said.
He claimed press freedom would not be threatened by the proposed bill because it would only apply during campaigns.
During last year's campaign Mr Macron was the subject of rumours about offshore banking which his party, En Marche, denounced as "fake news". He filed a legal complaint against his opponent, Marine Le Pen, for citing them publicly.
Speaking to journalists at the Elysee Palace, Mr Macron denounced the fact that "there is a financial strategy aiming at fostering doubt, forging alternative realities, that allows people to think that the media and politicians always are more or less deceptive".
He also said France and the European Union should consider "the consequences" of the recent US decision to eliminate net-neutrality protections for the internet, but did not elaborate.
"Press freedom is not only attacked by dictatorships, it is also battered in countries that are democracies" including in Europe, he said. He made a reference to Hungary and Poland and their recent crackdowns on media freedom.
