The French government has summoned the US ambassador to Paris, Charles Kushner, following American official statements about the death of far-right activist Quentin Deranque.
Mr Deranque, 23, died from head injuries sustained during clashes on the sidelines of a demonstration against a left-wing MP in Lyon on 12 February. French authorities have charged six men over the killing, along with a parliamentary assistant suspected of complicity.
The US embassy and the State Department's bureau of counter-terrorism posted on social media that "violent radical leftism is on the rise" and represented a threat to public safety. State Department under secretary for public diplomacy Sarah Rogers said the case demonstrated why political violence was treated so harshly.
In response, French foreign minister Jean-Noël Barrot said Paris rejected any attempt to use the tragedy for political ends. "We have no lessons to learn, particularly on the issue of violence, from the international reactionary movement," he told French media.
The killing has also strained relations with Italy, whose prime minister Giorgia Meloni described it as "a wound for all of Europe", drawing criticism from President Emmanuel Macron. Over 3,000 people marched in Lyon on Saturday in tribute to Mr Deranque, with heavy security deployed.
During the summons, Mr Barrot also plans to raise US sanctions against former European commissioner Thierry Breton and French judge Nicolas Guillou, describing them as "unjustified and unjustifiable". Mr Kushner was also summoned last August over a letter concerning antisemitism, though he did not attend personally.
