President-elect Donald Trump sent conflicting messages about his hopes for the supreme court on Sunday, saying he will appoint justices who will send abortion rights “back to the states” but conceding he was “fine” with marriage equality “because it was already settled”.

Trump made the comments in his first broadcast interview as president-elect, with CBS’s 60 Minutes, which aired on Sunday evening.

Trump also suggested he might retain parts of Barack Obama’s healthcare reforms, and said that he intends to deport as many as 3 million undocumented migrants with criminal records.

The supreme court has had eight members since the death of conservative justice Antonin Scalia in February. Senate Republicans have refused to even consider Obama’s nominee for the seat, Merrick Garland.

The vacant seat became a central campaign issue for conservatives, and CBS host Lesley Stahl asked Trump whether he would appoint a supreme court justice who wanted to overturn Roe v Wade, the 1973 case that upheld the right to abortion.

“So look,” Trump said. “Here’s what’s going to happen. I’m going to – I’m pro-life. The judges will be pro-life.”

Pressed, he said: “Having to do with abortion – if it ever were overturned, it would go back to the states. So it would go back to the states.” That did not mean women would not be able to get an abortion, Trump said, but “they’ll perhaps have to go, they’ll have to go to another state”.

“Well, we’ll see what happens,” he added. “It’s got a long way to go, just so you understand. That has a long, long way to go.”

In March, Trump suggested that women should face “some form of punishment” for having abortions, before reversing and saying states and Congress should lead lawmaking.

Asked by Stahl whether he supported marriage equality, which was made law by the supreme court in Obergefell v Hodges in 2015, Trump suggested the case did not concern him to the degree of Roe v Wade.

“It’s irrelevant,” he said, “Because it was already settled. It’s law. It was settled in the supreme court. I mean it’s done.”

Trump’s vice-presidential pick, Indiana governor Mike Pence, has opposed same-sex marriage throughout his career, and supported so-called “conversion therapy” programs that purport to change people’s sexual orientation.

Pence also signed a religious freedom law that sought to allow people to refuse service to same-sex couples because of religious convictions.

Trump, however, said he considered the matter resolved. “These cases have gone to the supreme court,” he said. “They’ve been settled. I’m fine with that.”

He was adamant, on the other hand, about gun rights, saying he wanted to stack the supreme court with justices that would defend those rights. “Everybody’s talking about the second amendment and they’re trying to dice it up and change it, they’re going to be very pro-second amendment,” Trump said.

Gun advocates last won a major battle in the supreme court in the 2008 case District of Columbia v Heller, which ended with a 5-4 ruling written by Scalia that broadly affirmed the personal right to firearms and overturned a handgun-possession ban in Washington DC.

Trump discussed a number of another issues in the CBS interview, including the brutal nature of the election campaign.

“Sometimes you have to be rougher,” he said, discussing his behaviour and choice of words in clashes with opponent Hillary Clinton and exchanges with Barack Obama, whom he met at the White House on Thursday, and wish for conciliation now.

Asked if he was still planning to appoint a special prosecutor to look into Clinton’s use of a private email server, a threat to which he added possible jail time when he made it in the second debate last month, he said he would “think about it”.

The president-elect wanted, he said, to “focus on all of these other things that we’ve been talking about”.