Speaking to other reporters ahead of a rally in Iowa Tuesday night, Trump said he viewed the killing of Pretti, an intensive care nurse at a veterans’ hospital, as “a very unfortunate incident”.

Asked by reporters about whether he agreed with characterisations of Pretti as a “domestic terrorist,” Trump said: “I haven’t heard that.”

Trump then added: “He shouldn’t have been carrying a gun.”

Homeland Security Secretary Kristi Noem said shortly after the shooting that Pretti “wasn’t there to peacefully protest, he was there to perpetuate violence,” and accused him of “domestic terrorism”.

The Department of Homeland Security (DHS) has also said the agents fired in self-defence, after Pretti resisted attempts to disarm him.

Noem said Pretti was shot because he was “brandishing” a gun during a confrontation. Eyewitnesses and local officials, however, have challenged that account, saying he had a phone in his hand, not a weapon.

There is no sign of a gun in Pretti’s hand, according to analysis of the available video by BBC Verify.