Republican presidential candidate Donald Trump has said that if abortions are made illegal in the US women who have them should be punished.
"There has to be some form of punishment," he said in a fierce exchange at a town-hall style event in Wisconsin.
Pressed by MSNBC's Chris Matthews on the nature of that punishment, Mr Trump responded: "I haven't determined what the punishment should be."
The property billionaire's comments provoked a torrent of condemnation.
Democratic White House front runner Hillary Clinton tweeted: "Just when you thought it couldn't get worse. Horrific and telling."
In the Wisconsin town hall, Mr Trump described himself as "pro-life with three exceptions", without specifying those clauses.
His campaign later issued statements that appeared to backtrack on his earlier remarks.
Mr Trump said if the US ever banned abortion "the doctor or any other person performing this illegal act upon a woman would be held legally responsible, not the woman".
"The woman is a victim in this case as is the life in her womb."
US abortion rights were enshrined in the Supreme Court's landmark 1973 ruling in Roe v Wade.
However, a number of states have passed measures over the years limiting access to pregnancy terminations.
And railing against Roe v Wade has become a matter of conservative orthodoxy for any Republican who runs for president.
Mr Trump has previously been criticised by his Republican rivals who say he is not conservative enough on abortion.
The real estate magnate's views on the hot-button issue have evolved.
In his 2000 book The America We Deserve, Mr Trump wrote that he supported a woman's right to choose.
But in 2011 he said he had changed his mind.
Mr Trump more recently said he believes abortion should be banned at some point in pregnancy, with exceptions for rape, incest or life of the mother.
He arrived in Wisconsin defending his campaign manager over an alleged assault.
The Midwestern state's 5 April primary could be a game-changer in the Republican race if Texas Senator Ted Cruz beats Mr Trump.
It could raise the prospect of the Republican nomination being decided by a contested convention, an extremely rare outcome that might plunge the party into civil war.
All three Republican candidates now say they aren't committing to supporting whomever the party chooses as its nominee for November's election.