President Donald Trump reportedly suggested shooting migrants in the legs and warding them off from the southern border with snakes or alligators during a tense week in March that marked a crossroads in his enforcement strategy on the southern border.

The New York Times reported Tuesday that the president was fuming after his aides tried to talk him out of shutting down the 2,000-mile US-Mexico border as a way of driving down the number of migrants attempting to cross it.

Trump eventually settled on threatening to impose tariffs on all Mexican goods as a way to pressure Mexico to step up its immigration enforcement efforts before ultimately backing off — but the solutions he proposed to his advisers in private were much more extreme.

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. After publicly suggesting that soldiers shoot migrants if they threw rocks, the president backed off when his staff told him that was illegal. But later in a meeting, aides recalled, he suggested that they shoot migrants in the legs to slow them down. That’s not allowed either, they told him.

The comments come from an excerpt from an upcoming book, Border Wars: Inside Trump’s Assault on Immigration, by the Times’s Michael Shear and Julie Hirschfeld Davis, who depict the president as frustrated by the limits of the law, cheering the Border Patrol’s decision to fire tear gas at a peaceful march of migrants trying to cross the border last November, and dismissive of officials in his administration who challenged him.

Trump denied having ever proposed creating a moat or an electrified fence on Tuesday, but said nothing of his suggestion to shoot down migrants.

Now the press is trying to sell the fact that I wanted a Moat stuffed with alligators and snakes, with an electrified fence and sharp spikes on top, at our Southern Border. I may be tough on Border Security, but not that tough. The press has gone Crazy. Fake News! — Donald J. Trump (@realDonaldTrump) October 2, 2019

Trump wasn’t able to get his way on the particular proposals detailed in the excerpt, but the administration has taken a series of drastic steps to prevent almost anyone at the southern border from obtaining asylum.

The Trump administration is sending migrants who line up at a port of entry or who are arrested when trying to cross the southern border back to Mexico to await decisions on their asylum claims. Under the policy, which is known as “Remain in Mexico,” the US has returned more than 42,000 migrants to Mexico as of September 1, according to US Customs and Border Protection.

A rule that prevents migrants from applying for asylum if they passed through another country other than their own before arriving in the US has also gone into effect across the entire southern border. That means that asylum seekers from any country but Mexico are ineligible for asylum if they show up at the border.

And the Trump administration has recently reached agreements with Honduras, El Salvador, and Guatemala that would require migrants on their way to the US to seek protections in those countries first, effectively cutting off their access to the American asylum system before they even reach the southern border.

More and more people are applying for asylum in recent years: about 157,000 this fiscal year as of July, compared to about 82,000 for all of fiscal year 2016. The number of migrants arrested while trying to cross the southern border is even higher, up to 811,000 this fiscal year through August from 553,000 in 2016. Most of them are families and unaccompanied children, whereas previously those arrested were primarily single adult men.