Wisconsin Gov. Scott Walker shown June 28 in his Capitol office in Madison, Wis. (Scott Bauer/AP)

Wisconsin Gov. Scott Walker (R) signed a bill Friday that requires women seeking abortions to obtain an ultrasound and mandates that doctors performing abortions have admitting privileges at a hospital within 30 miles, prompting opponents to quickly take legal action in hopes of blocking it.

"This bill improves a woman's ability to make an informed choice that will protect her physical and mental health now and in the future," Walker's office said in a statement announcing the signing of the bill, along with 17 other pieces of legislation.

The ultrasound requirement allows women to choose between transvaginal ultrasounds and less-invasive abdominal ultrasounds. It also bars physicians from performing abortions if they do not have admitting privileges at a hospital within a 30-mile radius.

Abortion-rights supporters swiftly criticized the move. The state's two abortion providers, Planned Parenthood of Wisconsin and Affiliated Medical Services, filed a lawsuit to fight the measure in federal court.