The Republican candidate in one of the most closely watched U.S. Senate contests came under pressure to drop out of the race Monday after saying on television that women's bodies are able to prevent pregnancies if they are victims of a ``legitimate rape.''

Congressman Todd Akin of Missouri apologized for the comments Monday, saying rape is ``never legitimate,'' but pledged to continue the race.

The Senate's top Republican, Mitch McConnell, said Akin's remarks about rape may ``prevent him from effectively representing'' the Republican Party. At least two Republican senators said he should resign the party's nomination.

Akin, a six-term congressman, is opposing Democratic incumbent Claire McCaskill in the November election. The race is seen as one of the Republicans' best chances of defeating a Democratic incumbent as they try to gain control of the Senate. Missouri is an increasingly conservative state and McCaskill has been targeted because of her strong ties to President Barack Obama.

``If it was me,'' Republican Chairman Reince Priebus told CNN, ``I would step aside and let someone else run for that office.''

Akin, who has served six terms, said he would not drop out.

``The good people of Missouri nominated me, and I'm not a quitter,'' he said. ``And my belief is we're going to take this thing forward and by the grace of God, we're going to win this race.''

As his political support waned, Akin also confronted problems paying for his campaign.

An official with the National Republican Senatorial Campaign Committee said the group's head, Sen. John Cornyn, called Akin on Monday to tell him that the committee had withdrawn $5 million in advertising planned for the Missouri race. The official spoke to The Associated Press on condition of anonymity because the conversation was private.

At least one outside group that has pounded McCaskill with ads also pulled its ads from Missouri.

Asked in an interview Sunday on KTVI-TV 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.''

Later Sunday, Akin released a statement saying that he ``misspoke'' during the interview, though the statement 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 believes ``deeply in the protection of all life'' and does ``not believe that harming another innocent victim is the right course of action.''

Moments after Akin's apology, President Barack Obama said Akin's comments underscore why politicians _ most of whom are men _ should not make health decisions on behalf of women.

``Rape is rape'' Obama said, adding that the idea of distinguishing among types of rape ``doesn't make sense to the American people and certainly doesn't make sense to me.''

Akin's comments also brought a swift rebuke from the campaign of presumptive Republican presidential nominee Mitt Romney and his running mate, Rep. Paul Ryan of Wisconsin. (AP)