US abortion laws are set for now, Republican presidential hopeful Donald Trump said, reiterating that he thinks abortion is "murder" days after igniting a firestorm by suggesting women who have them should be punished.

Trump has been criticized by abortion supporters and opponents for not being clear about his position on the hot-button political issue.

Abortions are still fiercely opposed by many Republicans, four decades after the US Supreme Court affirmed its legality nationwide.

"The laws are set now on abortion and that's the way they're going to remain until they're changed," Trump said in an interview with the NBC News program Face the Nation.

Later in the interview, which will air in full on Sunday, Trump said he agreed that "abortion is murder".

Hours after the interview excerpt was released on Friday, Trump campaign spokesperson Hope Hicks denied his candidate was backtracking on his opposition to abortion.

"Mr. Trump gave an accurate account of the law as it is today and made clear it must stay that way now -- until he is president," Hicks said. 

"Then he will change the law through his judicial appointments and allow the states to protect the unborn. There is nothing new or different here."

The 69-year-old Trump -- who has been a Democrat, a political independent and is only a recent convert to the "pro-life" anti-abortion position -- has been accused of flip-flopping on the issue.

Trump shocked many watchers in an interview on MSNBC, broadcast Wednesday, when he said "there has to be some form of punishment" for a woman who has an abortion.

The Trump campaign later issued a statement saying that if abortion were to become illegal under US law, then the doctor or any other person involved in performing the procedure would be legally responsible.

"The woman is a victim in this case as is the life in her womb," the statement read. "I am pro-life with exceptions."

Source: AFP