Wyoming has become the first US state to ban abortion pills.
Those who “prescribe, dispense, distribute, sell or use any drug for the purpose of procuring or performing an abortion” will face up to six months in prison and a fine of up to $9,000 (£7,300).
However, the law adds that women “upon whom a chemical abortion is performed or attempted shall not be criminally prosecuted”.
Wyoming’s Republican Governor Mark Gordon signed the bill into law after it was approved by state legislators earlier this month.
It comes in the wake of a US Supreme Court ruling last year that overturned the landmark 1973 Roe v Wade judgment, which granted the constitutional right of American women to have abortions.
Under Wyoming’s new law, “morning-after” pills, prescription contraceptive medication used after sex but before a pregnancy can be confirmed, will be exempted from the ban.
There will also be an exemption for treatment necessary to protect a woman “from an imminent peril that substantially endangers her life or health”, as well as any treatment of a “natural miscarriage according to currently accepted medical guidelines”.
As well as the ban on abortion pills, Governor Gordon allowed a separate and more sweeping measure restricting abortion to become law without his signature.
He said signing the bill would result in a lawsuit that will “delay any resolution to the constitutionality of the abortion ban in Wyoming”.
The state is currently pushing for more sweeping laws banning abortions, with an early abortion ban bill currently at the centre of a court battle.
The previous bill was blocked by the courts after providers claimed that the law violated the Wyoming state constitution’s guarantee of freedom in health care decisions.
Meanwhile, a federal judge in Texas is considering ordering a nationwide ban on the abortion pill mifepristone in response to a lawsuit by anti-abortion groups.
Wyoming American Civil Liberties Union (ACLU) advocacy director Antonio Serrano criticised Governor Gordon’s decision to sign the abortion pill law.
“A person’s health, not politics, should guide important medical decisions – including the decision to have an abortion,” Mr Serrano said.
Fifteen states already have limited access to abortion pills, including six that require an in-person physician visit, in the wake of the Roe v Wade judgment.
Since the reversal of the judgment, abortion restrictions have been up to states to set their own legislation, instead of the right to abortion being enshrined as a constitutional right.