LONDON — Britain’s deputy prime minister said Sunday that he told U.S. Vice President JD Vance he was wrong to blame immigration for the death of a university student who was handcuffed as he lay dying from a stab wound.

David Lammy, who is also the justice minister, said he challenged Vance in what he described as a “robust” phone call on Saturday. Lammy and Vance have struck up a friendship, based on their religious beliefs and family backgrounds, even though they come from different sides of the political spectrum.

“We had an agreeable conversation because we have got a relationship, but I wanted to make him clear that I disagree with some of the facts that he was asserting and to present the facts to him,” Lammy told Sky News.

The call came a day after Vance said in a post on social platform X that there should be “righteous anger” in response to the murder of Henry Nowak, 18, who died in December after being stabbed by Vickrum Digwa in the English city of Southampton.

Digwa, who is Sikh, falsely claimed to police he was the victim of a racist assault by Nowak, who was white. When police officers arrived, they initially treated the wounded man as a suspect before noticing his injury and trying to resuscitate him.

Vance appeared to blame the murder in part on “the mass invasion of migrants, many of whom despise the West and the people who love it.”

Lammy said he wanted to “emphasize a number of things” to Vance, including that the killer was British and is now behind bars.

“This has got nothing to do with mass migration,” Lammy said.

Digwa, 23, was convicted of murder for stabbing Nowak with an 8-inch (21 centimeter) Sikh dagger and sentenced this week to life in prison with a minimum 21-year term.

The case has been seized on by anti-immigration activists and politicians in the U.K. On Tuesday, police in Southampton were pelted with chairs, cans, rocks and flares after a demonstration over Nowak’s death attended by far-right figures and others.

In a statement issued Friday in response to Vance’s comments, Prime Minister Keir Starmer ‘s office criticized people “trying to interfere in our democracy and seeking to stir up division on our streets.”

The Independent Office for Police Conduct, which investigates allegations of police wrongdoing, is probing the actions of police officers on the scene.

The victim’s father, Mark Nowak, has said the case was not about racism or religion, and that he wanted his son’s death to lead to safer streets and not to be used to create “further division, hatred or tension.”

Lammy also said he told Vance “it’s not helpful to tweet in this way, partly because of what the Nowak family have asked for, and reminded him about their desire not to make this an issue of division and hatred, but to make this an issue of common sense.”