Presidential candidate Mitt Romney has called on fellow Republican Todd Akin to abandon his US Senate bid in Missouri after the congressman's comments about rape.
Akin has been under fire for his televised comments that women's bodies are able to prevent pregnancies if they are victims of "a legitimate rape".
Romney on Tuesday pointed to a statement from a group of current and former Missouri legislators who urged Akin to drop his bid against Democratic Senator Claire McCaskill.
Romney said: "I think he should accept their counsel and exit the Senate race."
Akin, however, vowed to stay in the contest, indicating he represents a conservative movement that must be heard.
"We are going to continue in this race for US Senate," he told the Mike Huckabee Show, a radio programme hosted by the former Arkansas governor, an Akin supporter and a favourite of religious conservatives.
Asked in an interview on Sunday on a local television station, KTVI, if he would support abortions for women who have been raped, Akin said: "It seems to me, first of all, from what I understand from doctors, that's really rare.
"If it's a legitimate rape, the female body has ways to try to shut that whole thing down."
In a statement later on Sunday, Akin said that he had "misspoke" during the interview, though he did not say specifically which points were in error.
"In reviewing my off-the-cuff remarks, it's clear that I misspoke in this interview, and it does not reflect the deep empathy I hold for the thousands of women who are raped and abused every year," Akin's statement said.
Akin also said he believed "deeply in the protection of all life" and does "not believe that harming another innocent victim is the right course of action".
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Akin's race against McCaskill is one of this year's most closely watched races as it represents one of the Republicans' best chances of defeating a Democratic incumbent as they try to gain control of the Senate.
McCaskill, who is seeking a second term, is considered vulnerable because of her strong ties to President Barack Obama, and the fact that Missouri is considered an increasingly conservative state.
Democrats quickly sought to capitalise on Akin's comments, with Obama saying the remarks underscore why politicians - most of whom are men - should not make health decisions on behalf of women.
Obama said "rape is rape" and the idea of distinguishing among types of rape "doesn't make sense to the American people and certainly doesn't make sense to me".
In an interview with National Review Online on Monday, Romeny had called Akin's comments "insulting, inexcusable and frankly wrong".
"Like millions of other Americans, we found them to be offensive," Romney said.