US President Donald Trump suggested shooting migrants in the legs to slow them down, according to a new book.
The book, by two New York Times journalists, says Trump suggested extreme methods of deterring migrants from crossing the southern border, the BBC reported on Wednesday.
They included building an electrified, spiked border wall and a snake or alligator-infested moat.
Building a wall on the border with Mexico is one of Trump's main policy objectives.
The construction of the wall has now begun, with the Pentagon allocating $3.6 billion of military funding towards its development.
The White House has not commented on the latest reports.
The book - called 'Border Wars: Inside Trump's Assault on Immigration', by reporters Michael Shear and Julie Davis, and based on interviews with more than a dozen unnamed officials - was published by the New York Times.
It chronicles a week in March 2019 when Trump reportedly tried to halt all southern migration to the US.
According to an excerpt, the president privately suggested to aides that soldiers shoot migrants in the legs, but he was told it would be illegal.
Previously, Trump had made a public statement suggesting soldiers shoot migrants who throw rocks.
Trump suggested other extreme measures, according to the book.
"Privately, the president had often talked about fortifying a border wall with a water-filled trench, stocked with snakes or alligators, prompting aides to seek a cost estimate. He wanted the wall electrified, with spikes on top that could pierce human flesh," reads the extract.
The excerpt describes Trump ordering aides to enforce a complete shutdown of the US-Mexico border by noon the following day, leaving advisers "in a near panic" and "desperately" trying to placate the president.
"Trump's order to close the border was a decision point that touched off a frenzied week of presidential rages, round-the-clock staff panic and far more White House turmoil than was known at the time," the excerpt says.
Aides reportedly managed to change Trump's idea of closing the border, but the President later pushed out a number of senior aides who he believed were frustrating his immigration crackdown, including Homeland Security Secretary Kirstjen Nielsen.