GOP vice presidential contender Paul Ryan declined to explain what is meant by "forcible rape" in abortion legislation he co-sponsored with embattled Rep. Todd Akin.

Ryan, a Wisconsin congressman, and Akin are among the 227 co-sponsors of the "No Taxpayer Funding for Abortion Act," which would prohibit federal funding of abortions except in instances of "an act of forcible rape or, if a minor, an act of incest."

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Akin, the GOP nominee for Senate in Missouri, touched off a furor with remarks Sunday about women's bodies being able to prevent pregnancy in cases of "legitimate rape." He has since apologized repeatedly for his remarks, but top Republicans -- including the GOP presidential ticket of Mitt Romney and Ryan -- have called on Akin to quit the race.

"Rape is rape. There is no splitting hairs over rape," Ryan told KDKA-TV in Pittsburgh, when asked twice about the "forcible rape" language and his opposition to abortion. The interview aired this morning.

Romney has said that if he is elected president that abortion would be allowed in cases of rape. During Ryan's first race for Congress in 1998, the Journal Sentinel newspaper reported Ryan was opposed to abortion in all instances except when the life of the woman is at stake.

"I stand by my pro-life record in Congress. It's something I'm proud of," Ryan told the Pittsburgh TV station. "But Mitt Romney is the top of the ticket and Mitt Romney will be president of the United States and he will set the policy of the Romney administration."

Ryan, who called Akin and urged him to quit the Missouri Senate race, said Akin's comments were "outrageous, over the pale."