Story highlights The decision to veto the bill comes at a time when Fallin is considered a possible running mate for Donald Trump

Fallin said in a statement that the bill is "vague" and "ambiguous"

Washington (CNN) Oklahoma Gov. Mary Fallin on Friday vetoed a bill that would criminalize abortion procedures in the state.

The decision to veto the bill, which likely would have opened up the state to lawsuits from abortion rights supporters, comes at a time when Fallin is considered a possible running mate for presumptive GOP presidential nominee Donald Trump.

"The bill is so ambiguous and so vague that doctors cannot be certain what medical circumstances would be considered 'necessary to preserve the life of the mother,'" Fallin, a Republican, said in a statement.

The Oklahoma state legislature passed the legislation on Thursday. According to the bill's language, anyone who is found to have performed an abortion -- except in instances to save the life of the mother -- would be found guilty of a felony and could receive up to three years in prison.

"This bill is as direct an assault on Roe v. Wade -- and the Supreme Court's subsequent jurisprudence -- as anything we've seen before. If this law is upheld, then (the Roe decision) is meaningless," Steve Vladeck, a CNN contributor and law professor at the American University Washington College of Law, said Thursday.

Read More