The diplomatic row began when the US embassy to France posted comments on social media about the murder of far-right nationalist Quentin Deranque.
The post warned that “violent left-wing extremism is on the rise” in France.
Deranque, a 23-year-old maths student, died in hospital on 14 February – two days after being beaten by a gang of masked young men in Lyon, in an attack which ministers from France’s centre-right government have blamed on “far-left” militants.
But the US embassy’s comments appear to have angered the French government.
“We reject any use of this tragedy, which has plunged a French family into mourning, for political ends,” Barrot said over the weekend.
“We have no lessons to learn, particularly on the issue of violence, from the international reactionary movement,” he added.
BBC News has approached the US embassy to France for comment.