Pro- and anti-abortion-rights activists rally face to face in front of the U.S. Supreme Court in Washington on the 40th anniversary of the landmark 1973 Roe v. Wade decision that legalized abortion nationwide. Manuel Balce Ceneta/AP

The U.S. Supreme Court on Monday sidestepped what would have been its first abortion case since 2007, declining a case about overturned restrictions on the RU-486 abortion pill.

The dismissal means that last week's Oklahoma Supreme Court ruling, which invalidated a 2011 state law restricting medical abortions, is final. The state supreme court said the law violated the Constitution by effectively banning abortion-inducing drugs.

In a one-line order on Monday, the Supreme Court dismissed the Oklahoma case, Cline v. Oklahoma Coalition for Reproductive Justice, as "improvidently granted."

The Center for Reproductive Rights, the group that had challenged the law, said the Supreme Court's action means women in Oklahoma will once again have access to drug-induced abortions and nonsurgical treatment for ectopic pregnancies — when an embryo implants outside the uterus — which are usually not viable.

"The Supreme Court has let stand a strong decision by the Oklahoma Supreme Court that recognized this law for what it is: an outright ban on a safe method of ending a pregnancy in its earliest stages and an unconstitutional attack on women's health and rights," the group's president, Nancy Northup, said in a statement.

The RU-486 "abortion pill" differs from the emergency contraception "morning-after pill" in that the former may be used, in tandem with another drug, to induce abortion up to seven weeks into a pregnancy.

In June the Supreme Court said it would review the case but first asked the state court to clarify what exactly the state law prohibited and whether it conflicted with U.S. Food and Drug Administration guidance.

By declining now to hear the case, the United States' highest court signaled that while it would not shy away from reviewing abortion regulations in some instances, it is not eager to revisit earlier disputed decisions on the right to abortion in general terms.

Republican Oklahoma Attorney General Scott Pruitt, who defended the law, did not immediately respond to a request seeking comment.