A 6-week abortion ban was signed into legislation Tuesday in North Dakota by Republican Governor Jack Dalrymple, making it the nation's most restrictive abortion laws.

The bill refuses the abortion procedure if a fetal heartbeat can be detected, which can be six weeks into a pregnancy. Also is the first state to ban abortions on genetic defects such as Down syndrome and require abortion doctors to have hospital admitting privileges.

The measure will take effect August 1 and Dalrymple acknowledged it has faced a fierce fight from pro-choice activities. He said the law is a direct challenge to the 1973 U.S. Supreme Court ruling on abortion of Roe v. Wade.

"Although the likelihood of this measure surviving a court challenge remains in question, this bill is nevertheless a legitimate attempt by a state legislature to discover the boundaries of Roe v. Wade," Dalrymple said according to CBS News. "Because the U.S. Supreme Court has allowed state restrictions on the performing of abortions and because the Supreme Court has never considered this precise restriction ... the constitutionality of this measure is an open question."

The abortion-rights advocates include national reproduction rights groups including The Center for Reproductive Rights, planning to take a legal challenge before it comes to effect.

The controversial move by Dalrymple comes following the state legislature's approval to outlaw abortion in the state by passing a resolution defining life as starting at conception. If approved by North Dakota residents in 2014, then will be the first to place a complete ban in the country.