Donald Trump set out a stark vision for an authoritarian second term in an interview with Time magazine published on Tuesday, ranging from possible mass deportations of migrants by the US military and detention camps to pregnancy monitoring to enforce abortion bans.

The Republican former president, who will face Democrat incumbent Joe Biden in November's election, also warned of a crackdown on the "enemy from within" if he secures a White House comeback and failed to rule out political violence if he does not.

Trump, 77, was in court in New York Tuesday for his porn star hush money trial. The interview took place at his Florida home in early April and then by telephone, giving an unusually detailed view of the policies that he normally only paints in broad strokes during campaign rallies.

"I think the enemy from within, in many cases, is much more dangerous for our country than the outside enemies of China, Russia, and various others," Trump said in the interview when asked if he would be willing to suspend parts of the US Constitution to deal with opponents.

On immigration, a potentially decisive issue in the 2024 election amid record numbers of people illegally crossing the southern US border with Mexico, Trump said he would have "no choice" but to launch mass deportations.

This would primarily involve the US National Guard "but if I thought things were getting out of control, I would have no problem using the military," Trump said.

"These aren’t civilians. These are people that aren't legally in our country. This is an invasion," Trump told Time magazine when the interviewer pointed out that US laws prevent the military from being used against civilians on US soil.

Trump said he "would not rule out anything" on setting up migrant detention camps but believed they would not be necessary because his deportation program would be successful.

Abortion bans

On abortion, another hot-button election topic, Trump repeated his stance that he would leave the issue for the individual US states to decide whether to prosecute those who violate bans on the procedure. 

Trump has claimed credit after the conservative-leaning US Supreme Court featuring three Trump-appointed judges overturned the federal right to abortion in 2022, prompting several Republican-led states to introduce full or partial bans.

Asked if states should monitor women's pregnancies to see if they have had abortions in defiance of a ban, Trump replied: "I think they might do that."

He would not commit to vetoing any attempt to introduce a nationwide US abortion ban. 

Trump meanwhile refused to rule out the possibility of unrest if he loses in November. His supporters attacked the US Capitol on January 6, 2021, in a bid to overturn his election loss to Biden.

Trump said that "I think we're going have a big victory and I think there will be no violence" -- but when pushed, added that "if we don't win, you know, it depends."

The Republican, who was impeached over the January 6 unrest, also failed to rule out prosecuting Biden if he wins the election.

"Biden, I am sure, will be prosecuted for all of his crimes, because he's committed many crimes," he added, without specifying them.