Missouri Republican Rep. Todd Akin apologized Monday for comments he made about "legitimate rape" over the weekend, but rejected growing clamor even from fellow Republicans for him to abandon his Senate bid.

Akin, who's been embroiled in an uproar since suggesting that "legitimate rape" rarely results in victims' pregnancy, acknowledged he made "serious mistakes" in responding to a question about his stance on abortion rights in cases on rape.

"I made that statement in error. Let me be clear: rape is never legitimate; it's an evil act that's committed by violent predators," Akin said on former Arkansas Gov. Mike Huckabee's radio show. "I used the wrong words in the wrong way. What I said was ill-conceived and it was wrong, and for that, I apologize."

The Cycle hosts discuss Rep. Todd Akin's comments this past weekend that pregnancy was not common in cases of "legitimate rape."

Akin first told KTVI-TV on Sunday: “First of all, from what I understand from doctors, [pregnancy from rape] is really rare. If it’s a legitimate rape, the female body has ways to try to shut that whole thing down."

The Missouri congressman said Monday that he understood that it was possible for pregnancies to result from an instance of rape.

But the six-term congressman, who bested two other candidates in a GOP Senate primary earlier this month, resisted dropping his campaign to unseat incumbent Democratic Sen. Claire McCaskill.

"I feel just as strongly as ever that my background and ability will be a big asset in replacing Claire McCaskill and putting some sanity back in what's going on in our government," Akin said, explaining that no national Republican figure had specifically called to demand his resignation. "The good people of Missouri nominated me, and I'm not a quitter. And my belief is we're going to take this thing forward, and by the grace of God, to win this race."

In a statement and a Tweet, conservative congressman Todd Akin says he "misspoke" during a local TV interview in which he made comments about "legitimate rape" and abortion. NBC's Kelly O'Donnell reports.

However, two Senate Republicans have already said Akin should abandon his Senate bid. Massachusetts Sen. Scott Brown and Wisconsin Sen. Ron Johnson both called for Akin to resign his Senate nomination. (If he were to do so by Tuesday, Republicans would have a clearer path toward nominating a new candidate.)

Texas Sen. John Cornyn, who heads the GOP's Senate campaign efforts, called Akin's statements "wrong, offensive, and indefensible." He called on Akin to "carefully consider what is best for him, his family, the Republican Party, and the values that he cares about and has fought for throughout his career in public service."

Former congresswoman and current Senate candidate from New Mexico, Heather Wilson, has also called on Akin to step aside.

Sen. Claire McCaskill, D-Mo., joins Morning Joe to discuss Rep. Todd Akin's, R-Mo., statement that "legitimate rape" rarely results in pregnancy, which he said during a television interview.

Other Republicans have also been critical of Akin, including presumptive Republican presidential nominee Mitt Romney, who called the congressman's remarks "inexcusable." Romney will not call for Akin to step down from the race, though, adviser Stu Stevens told reporters in New Hampshire.

President Barack Obama, during an appearance Monday afternoon in the White House briefing room, also condemned Akin's remarks.

"The views expressed were offensive. Rape is rape," said Obama. "And the idea that we should be parsing and qualifying and slicing what types of rape we're talking about doesn't make sense to the American people. And certainly doesn't make sense to me."

NBC's Peter Alexander contributed to this report.