Donald Trump lays stones and flowers at memorial to 11 killed in Pittsburgh Tree of Life synagogue shooting

White House spokesperson Sarah Sanders told reporters: "The president was very moved by the visit and his time with the rabbi and called it very humbling and sad."

But Mr Trump's visit prompted anger from those who accused him of stoking hatred. An estimated 4,000 people protested in the city's Squirrel Hill neighbourhood, as he paid his respects.

One protestor carried a sign saying Mr Trump should "apologize for stoking hatred or go home" and another carried one saying: "You know who else was a nationalist? Hitler"

One speaker told the crowd: "Your words and your policies have emboldened the white nationalist movement."

It was organised by Bend the Arc, a group of progressive Jews who previously wrote an open letter urging the president not to visit.