"The more he (Trump) makes this sort of statement, the more Europeans close ranks," Sapin told reporters, according to Reuters.
Trump said German Chancellor Angela Merkel had made a "catastrophic mistake" with her open door policy on migration, according to an interview published Sunday by the Times of London and German newspaper Bild.
Sapin said such criticism was unacceptable. "The attack on the Chancellor is not an argument we can accept as Frenchmen or as Europeans," he said.