DELAWARE, Ohio — Mitt Romney assured Wednesday he would be a "pro-life president" if he defeats President Barack Obama, reaffirming his opposition to abortion a day after suggesting he could moderate his platform.

But when asked directly if he would restrict legislation limiting abortion rights if such a bill came to him from Congress, the Republican challenger's response was less clear cut.

"I think I've said time and again that I'm a pro-life candidate and I'll be a pro-life president," Romney told reporters while campaigning in Ohio.

Obama swiftly said his White House rival was "hiding positions he's been campaigning on for a year and a half."

A Republican Party primary process early this year featured a debate about hot-button social issues like abortion and religion, as the candidates, including Romney, sought to woo their party's conservative base.

Once Romney won the nomination outright, the clamor died down and social issues took a back seat to the US economy and international crises like Syria and Libya.

But abortion, an explosive topic in American politics, roared back to the fore this week, beginning Tuesday with Romney's remarks to The Des Moines Register.

During a campaign stop in the battleground state of Iowa, he told the paper: "There's no legislation with regards to abortion that I'm familiar with that would become part of my agenda."

The statement marked a noteworthy shift for Romney.

While he ran on a pro-choice platform during his successful campaign for governor of Massachusetts, he firmly declared his pro-life position shortly after his governorship.

Romney told a Republican debate in January that the 1973 US Supreme Court decision legalizing abortion should be overturned and that the decision should rest with the states.

With Romney campaigning in key battlegrounds Iowa, Ohio and North Carolina this week, and polls showing Obama ahead among women voters, analysts said the Republican nominee was tempering his position in order to attract undecided and women voters less than four weeks from the November 6 election.

The president said abortion was one of the issues on which Romney has recently tried to "cloud" his position.

"This is another example of governor Romney hiding positions he's been campaigning on for a year and a half," Obama told ABC's "World News."

But the president did not claim Romney was lying.

"I actually think, when it comes to women's rights to control their own health care decisions, you know, what he has been saying is exactly what he believes," said Obama.

Romney "thinks that it is appropriate for politicians to inject themselves in those decisions," he added.

While dodging the abortion legislation question Wednesday, Romney said he would act "immediately... to remove funding for Planned Parenthood," a non-profit group that performs abortions and other women's health care.

"And also I've indicated I'll reverse the Mexico City position of the president," he added. "I will reinstate the Mexico City Policy."

In the early days of his presidency, Obama rescinded the rule, which prohibited non-profit groups from receiving federal government funds that went to providing abortions in other countries.

Cecile Richards, president of the Planned Parenthood Federation of America, accused Romney of hypocritical doublespeak about women's rights.

"He has been incredibly dishonest about where he stand," she said.

"There is no way for him to hide from the positions he has taken over the years."