Media playback is unsupported on your device Media caption Donald Trump shifts again on abortion

Presidential hopeful Donald Trump has said US abortion laws should remain unchanged, although he believes the procedure amounts to murder.

In an interview with CBS News, Mr Trump said: "The laws are set. And I think we have to leave it that way".

His comments come as Mr Trump has struggled this week to articulate his position on abortion.

He withdrew a call for women who have abortions to be punished, only hours after suggesting it.

After an outpouring of criticism from both anti-abortion and abortion rights activists, Mr Trump later said only the people who perform abortions should face punishment.

The comments end a rocky week for Mr Trump on the campaign trail.

According to some polls, he is trailing Texas Senator Ted Cruz by 10 percentage points in Wisconsin, which holds its primary on Tuesday.

Democratic presidential candidates Hillary Clinton and Bernie Sanders, and Mr Trump's Republican rivals Mr Cruz and John Kasich repeatedly criticised Mr Trump's shifting comments on abortion.

Mr Cruz said the remarks showed that Mr Trump "hasn't seriously thought through the issues".

Mr Kasich - the popular governor of Ohio - also questioned whether Mr Trump had the temperament needed for the office of the president.

Image copyright EPA Image caption Mrs Clinton has seized on Mr Trump's comments on abortion

The Republican front-runner supports a ban on abortions, with some exceptions.

Only the Supreme Court or a constitutional amendment has the power to overturn Roe v Wade and make abortion illegal.

After the comments were made public, Mr Trump's spokeswoman Hope Hicks sought to clarify his statement.

Ms Hicks said that Mr Trump would change abortion laws if elected by appointing Supreme Court justices who would overturn Roe v Wade.

Once a Democrat, Mr Trump has been criticised for supporting abortion rights in the past.

Anti-abortion activists have traditionally avoided placing blame on women who undergo abortions, but have focused on those who perform the procedure.

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In recent years, conservatives have sought to tighten restrictions on abortion clinics and doctors rather than seek an outright ban.

Abortion rights advocates say these measures are meant to restrict women's access to abortion.

The new laws are particularly widespread in conservative southern states.

Republican leaders have expressed concern about Mr Trump's prospects in the general election because polls show that the New York businessman is extremely unpopular with female voters.

Mr Trump has come under fire for disparaging women including former presidential candidate Carly Fiorina and TV presenter Megyn Kelly.

His campaign manager, Corey Lewandowski, was arrested on Tuesday, accused of a minor assault on a female reporter. Mr Trump has vehemently defended Mr Lewandowski.