North Carolina Governor Pat McCrory said on Wednesday he will sign a law requiring pregnant women to wait three days between consulting a doctor and having an abortion, among the longest waiting periods in the nation.

McCrory, a Republican, faced intense lobbying from pro-choice advocates who hoped he would veto the measure, citing his campaign promise not to sign any further restrictions on abortion.

But in a statement released late Wednesday, McCrory said that the final version of the bill met his approval. He noted that he had worked with legislators to ensure that initial contact made with a health care provider could be a phone call, so the law would not require separate office visits.

"Some very positive progress was made during the last several days to protect women's health," McCrory said. "Therefore, I will sign this bill."

Once the measure becomes law, North Carolina will join Missouri, South Dakota and Utah in requiring a 72-hour waiting period. Last month, Oklahoma also adopted a 72-hour waiting period. A total of 24 states require some waiting period before an abortion can be performed, and several are considering new or longer restrictions this year.

North Carolina's bill triples the state's current 24-hour waiting period. McCrory's vow to sign it came after the state House of Representatives gave its final approval, agreeing to slightly modified form that passed the Senate on Monday. The house initially approved the bill in April. All three votes fell largely along party lines.

Protesters rallied on Wednesday in Raleigh and in Charlotte, where McCrory was once mayor, to urge a veto. At one rally, the side of a truck bore McCrory's image alongside his campaign promise.

Critics noted that McCrory signed into law a previous measure tightening regulation of abortion clinics. In a statement urging McCrory to veto the waiting period bill, Nancy Northup, president of the Center for Reproductive Rights, said he was being given "a second chance to make good on his promise not to interfere with women's access to safe, legal, essential health care".

"No one should be forced to delay health care because politicians have the audacity to presume to know what is best for a woman and her family," said Northup, whose organization advocates for abortion rights, in a statement.