The National Rifle Association (NRA) has joined other US gun lobby groups in calling for a "full investigation" by the Trump administration into the killing of Alex Pretti in Minnesota.

Comments from the NRA come after a border agent fatally shot Pretti - registered nurse at a Veterans Affairs hospital - in Minneapolis on Saturday.

State and federal officials have given starkly different accounts. The Trump administration has said Pretti carried a gun and posed a danger to officers - while no available video shows Pretti holding a gun.

The NRA labelled a suggestion by a federal prosecutor that people who carry guns risk being lawfully shot by officers as "dangerous and wrong".

"Responsible public voices should be awaiting a full investigation, not making generalisations and demonising law-abiding citizens," the NRA said in a statement.

The NRA - which is typically aligned with Donald Trump - was reacting to comments from First Assistant US Attorney for the Central District of California on Saturday night.

Bill Essayli wrote on social media: "If you approach law enforcement with a gun, there is a high likelihood they will be legally justified in shooting you. Don't do it!"

In a separate social-media post, the NRA said: "As there is with any officer-involved shooting, there will be a robust and comprehensive investigation that takes place to determine if the use of force was justified.

"As we await these facts and gain a clearer understanding, we urge the political voices to lower the temperature to ensure their constituents and law enforcement officers stay safe."

Essayli's comments have drawn criticism from other gun advocacy groups, as well as politicians from across the spectrum.

Gun Owners of America said in a statement: "The Second Amendment protects Americans' right to bear arms while protesting - a right the federal government must not infringe upon."

Republican Thomas Massie said: "Carrying a firearm is not a death sentence, it's a constitutionally protected God-given right, and if you don't understand this you have no business in law enforcement or government."

In a follow-up social media post, Essayli accused critics of taking his comments out of context.

"I never said it's legally justified to shoot law-abiding concealed carriers," he said on X. "My comment addressed agitators approaching law enforcement with a gun and refusing to disarm."

For the second time this month, federal agents have been involved in a fatal shooting in Minneapolis linked to a crackdown on illegal immigration by the Immigration and Customs Enforcement (ICE) agency.

Bystander video footage has captured the moments before Pretti was shot on Saturday.

The altercation that led to Pretti's shooting was recorded from many points of view and federal and state officials have given conflicting accounts.

The Department for Homeland Security shared an image of a gun it claimed belonged to Pretti and said he was a threat to officers.

On Saturday, Homeland Security Secretary Kristi Noem was asked to clarify if Pretti had brandished a gun and said agents fired what she called "defensive shots" while trying to disarm Pretti.

"They responded according to their training, and took action to defend the officer's life and those of the public around him. And, I don't know of any peaceful protester that shows up with a gun and ammunition rather than a sign."

Minnesota Governor Tim Walz branded the Trump administration's version of events "nonsense" and "lies."

Minneapolis Mayor Jacob Frey likened the federal operation to an invasion and accused ICE of "trying to spin this as an action of self-defence".