US President Donald Trump suggested shooting migrants in the legs to slow them down, according to a new book.

Axar.az reports citing BBC that the book, by two New York Times journalists, says Mr. Trump suggested extreme methods of deterring migrants from crossing the southern border.

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 Mr. Trump's main policy objectives.

The construction of the wall has now begun, with the Pentagon allocating $3.6bn (£2.9bn) of military funding towards its development.

The White House has not commented on the latest reports.

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, Mr. Trump had made a public statement suggesting soldiers shoot migrants who throw rocks.