Days after saying that abortion policies should be left to the states, former President Donald J. Trump on Wednesday criticized an Arizona court ruling for upholding an 1864 law that banned nearly all abortions and said he would not sign a national abortion ban if he were elected president.

Speaking to reporters on an airport tarmac in Atlanta, Mr. Trump said he expected that the Arizona law would be “straightened out.” He also said he expected that a six-week abortion ban in Florida that he has criticized was “probably, maybe going to change.”

Yet even as he suggested his disapproval with the circumstances in both states, Mr. Trump defended the position he took in a video statement on Monday, when he said that states should weigh in on abortion through legislation.

“It’s the will of the people. This is what I’ve been saying,” Mr. Trump said in Atlanta, where he had traveled for a fund-raiser. “It’s a perfect system.”

Mr. Trump’s comments, coming after his Monday statement, continued months of mixed signals on abortion, an issue that his campaign has worried could hurt him at the polls in November.

After the Supreme Court overturned Roe v. Wade in 2022 — a decision made possible by Mr. Trump’s appointment of three conservative justices to the bench — Democrats have made attacks against Mr. Trump on the issue central to their efforts to mobilize voters in November.

During campaign speeches and interviews, Mr. Trump often takes credit for appointing the justices and for, in effect, returning the issue of abortion to the states. But the Biden campaign and the Democrats have repeatedly laid the blame for strict state abortion laws on Mr. Trump, including the Florida ban, which the former president has called a “terrible mistake.”

Their efforts to tie him to stringent restrictions accelerated after his comments on Monday and after the Arizona court ruling on Tuesday, which said “all abortions, except those necessary to save a woman’s life, are illegal,” in accordance with a 160-year-old law.

Michael Tyler, a spokesman for the Biden campaign, said in a statement after Mr. Trump’s comments on Wednesday that Mr. Trump “owns the suffering and chaos happening right now, including in Arizona, because he proudly overturned Roe.”

Democrats have also used the ambiguity left by Mr. Trump’s state-focused position to suggest that he would be open to signing a federal abortion ban if he won in November, which anti-abortion groups have pushed for.

When he was in the White House, his administration backed a bill that would have banned nearly all abortions after 20 weeks of pregnancy, and penalized anyone who performed the procedure.

But with Roe overturned and Republicans seeming to suffer political consequences in the fallout, Mr. Trump has been trying to stake out a position that would animate his conservative base without turning off moderate voters.

Last month, he suggested he would be open to backing a 15-week federal ban with exceptions for rape, incest and life-threatening emergencies. But that idea was absent from his statement on Monday.

Mr. Trump, a Florida resident, has not yet said how he might vote this November on a ballot measure there that would enshrine abortion rights in the state’s Constitution. Of Arizona, he said the law was “going to definitely change,” adding, “Everybody wants that to happen. And you’re getting the will of the people. It’s been pretty amazing.”

He avoided expounding on his personal views later on Wednesday at a campaign stop at a Chick-fil-A restaurant in Atlanta. When asked by a reporter whether he believed doctors should be punished for providing abortions, Mr. Trump said that question should be left to the states.

“Those are the things that the states are going to make a determination about,” he said.