The registered Republican voter asked Trump "what protections would be put in place or kept" for mothers with high-risk pregnancies whose lives are in jeopardy, if Roe is overturned.
President Trump did not answer what "protections" he might consider, and declined to say whether Roe would be reversed.
"I'm not ruling on this," he said adding that he had not spoken to previous Supreme Court nominees about Roe.
Trump recently nominated a Catholic federal circuit court judge, Amy Coney Barrett, to fill the Supreme Court vacancy left by the death of the late Justice Ruth Bader Ginsburg. The Senate Judiciary Committee wrapped up a series of hearings on Barrett's confirmation on Thursday, with a committee vote expected on Oct. 22.
At those hearings, Barrett refused to opine on Supreme Court cases so as not to give a "forecast" of how she might rule on the bench if an abortion case appeared before her.
Trump said on Thursday that he did not want to "influence" any future decision by Barrett, as she has yet to be confirmed by the Senate.
"I would like to see a brilliant jurist, a brilliant person, who has done this in great depth and has actually skirted this issue for a long time, make a decision. And that's why I chose her [Barrett]," Trump said. "I did not tell her what decision to make, and I think it would be inappropriate to say right now, because I don't want to do anything to influence her."
Anticipation that the Supreme Court could reconsider Roe, the 1973 ruling that legalized abortion in all 50 states, has grown in recent years. In 2019, Alabama enacted a ban on nearly all abortions in the state in what was seen as an attempt to bring a challenge to Roe before the Supreme Court.
At a 2016 presidential debate, Trump promised to appoint "pro-life" Supreme Court justices who could eventually overturn Roe v. Wade.
"If we put another two, or perhaps three, justices on [the Court]," Trump said, "that'll happen automatically, in my opinion, because I am putting pro-life justices on the Court," Trump said of repealing Roe.
On Thursday, however, he demurred on the question of repealing Roe.
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"I think, depending on what happens with Roe v. Wade, I think that it could get sent down to the states, and the states would decide. I also think perhaps nothing would happen," Trump said.
Another audience member asked Trump about the Deferred Action for Childhood Arrivals (DACA) program. The administration in 2017 said it would wind down the program and gave Congress a six-month window to enact parts of the program into law, which it failed to do.
In June, the Supreme Court said the administration's effort to end DACA was unlawful and sent the matter back, saying that it could still end the program but had to do so lawfully.
A woman who said she was the daughter of immigrants who fled persecution in Poland and Russia asked Trump if his administration would continue trying to end DACA in his second term.
"We are going to take care of DACA. we're going to take care of Dreamer [sic]," Trump said without specifying what actions his administration would take on the program. He then mentioned that more than 400 miles of border wall have been constructed in his first term.
When NBC moderator Savannah Guthrie noted that no new DACA applicants are currently allowed, Trump answered that "we want people to come into our country" but to do so "legally" and on a "merit system."