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.

US ambassador Charles Kushner, the father of US President Donald Trump’s son-in-law, was ordered to report to the French foreign ministry on Monday.

But, as Kushner was absent, the US embassy’s charge d’affaires went in his place and was received by two French foreign ministry directors, a French diplomatic source said.

The row erupted amid concerns about an increase in antisemitic acts and hate crimes in France as international tensions mount over the conflict in Gaza. Kushner, in a public letter to French President Emmanuel Macron, has accused France of a “lack of sufficient action”.

France retorted that “the allegations from the ambassador are unacceptable” and the rift deepened on Monday when Kushner was summoned to the ministry and the Trump administration doubled down on his critique.

“We stand by his comments,” said Tommy Pigott, deputy State Department spokesman. “Ambassador Kushner is our US government representative in France and is doing a great job advancing our national interests in that role.”