There are still some 600 migrants — mostly young Eritreans, Sudanese and Afghans — in and around Calais, camping out in the underbrush and scattering at the approach of the police. Still, they are invisible in the struggling town itself, where before knots of two or three were ever-present.

But Mr. Macron, at times sounding defensive, seemed most at pains to reassure his critics on the left in his speech Tuesday, in a frigid and drafty hangar at a windswept police barracks in Calais.

The president is not used to being accused of inhumanity, but that has been the tenor of a weekslong barrage in the media here. His face appeared on the cover of this week’s widely read magazine L’Obs encased in barbed wire; inside, a host of well-known writers took savage aim at him.

In Le Monde on Tuesday, leading intellectuals, including a one-time top adviser and the head of a top think tank, accused him of having “broken with the humanism you advocated.”

So on Tuesday Mr. Macron’s most pointed words were for the police officers who listened to him in stony silence, and did not applaud him at the end.

The unspoken message to them: be gentle. It was an unusual admonition in the French context — a head of state chiding national law enforcement, with which a French president usually tries to closely identify.