A diplomatic row between the United States and France escalated on Monday when Washington decided to stand firmly behind its ambassador's criticism of the French response to a rising tide of antisemitism.

France has summoned the US ambassador Charles Kushner after he sent a letter criticising the French government for allegedly not doing enough to counter antisemitism. The US envoy, a real estate tycoon whose son Jared is married to US President Donald Trump's daughter Ivanka, made his comments public on Sunday.

Kushner wrote in an open letter on Sunday to President Emmanuel Macron that the country had not taken “sufficient action” to combat antisemitism.