Abortion rights should be left up to US states to decide, Republican presidential candidate Donald Trump said Monday, effectively rejecting a national abortion ban after months of mixed signals on one of the November election's most contentious issues.

"My view is now that we have abortion where everybody wanted it from a legal standpoint, the states will determine by vote or legislation or perhaps both," the likely Republican presidential nominee said in a video posted on his Truth Social network.

"And whatever they decide must be the law of the land, in this case, the law of the state."

His statement came after questions had swirled for weeks over what his stance would be on the issue.

They were fueled by a New York Times article in February that said he had told advisers he liked the idea of a 16-week national abortion ban but was hesitant to address it publicly lest he alienate socially conservative supporters.

A shock ruling by the US Supreme Court in 2022 -- boosted by three Trump nominees -- overturned Roe v Wade, which enshrined the federal right to abortion, and left it to states to establish their own laws on reproductive rights.

Some have enacted near-total bans while others, like Maryland, passed laws to enshrine abortion rights. Many conservatives hope a national ban could override laws like Maryland's.

But a comfortable majority of Americans think abortion should be legal in most cases, according to extensive polling, and around half of states have measures in place to protect access.

- Exceptions -

Trump's rival for the White House, US President Joe Biden, is a devout Catholic but as president has stood firm in his support for abortion access.

Democrats have been leaning strongly into the issue -- characterizing Trump as the architect of attacks on reproductive rights, while vowing to reinstate Roe.

Since Roe fell, abortion rights advocates have won seven straight referendum victories.

Meanwhile, Republicans have struggled to stake out a definitive position on the issue, and were punished in the 2022 midterm elections as candidates lost key battlegrounds to rivals supporting abortion rights.

In his video, Trump repeated earlier comments that, like former Republican president Ronald Reagan, when it comes to abortion he is "strongly in favor of exceptions for rape, incest and the life of the mother."

And he said again that he "strongly" supports IVF access for "couples who are trying to have a precious baby."

Experts say the Supreme Court ruling effectively granted states the final say on questions of personhood, paving the way for wide-reaching impacts on other areas of reproductive health, including in vitro fertilization.