Republican lawmakers in the southern US state of Louisiana gave final approval Thursday to a bill that would criminalize possession of abortion pills without a prescription.

The legislation, passed 29-7 by the state senate and 64-29 in the state house, is the first in the country to classify the drugs as controlled and dangerous substances.

It is expected to be signed by Republican Governor Jeff Landry.

The bill, which comes as abortion rights are being hotly debated ahead of November's presidential election, reclassifies mifepristone and misoprostol, commonly used for abortions, as Schedule IV drugs -- putting them on a par with Valium and Xanax. 

Possession of the medication without a prescription would be punishable by up to five years in prison and a $5,000 fine.

Authorized medical practitioners would be exempt from prosecution, as would pregnant women if they had the medication for their own use.

Medication abortion accounted for 63 percent of the abortions in the United States last year, up from 53 percent in 2020, according to the Guttmacher Institute.

Vice President Kamala Harris criticized the Louisiana law in a post on X on Tuesday after it was passed by the state House, calling it "absolutely unconscionable."

"Let's be clear: Donald Trump did this," added Harris, who has previously criticized Trump for boasting of his role in appointing the Supreme Court justices who reversed Roe v Wade, the landmark ruling that enshrined the constitutional right to abortion for half a century.

Some 20 states have banned or restricted abortion since the Supreme Court overturned Roe v. Wade in June 2022.

Abortion is banned in conservative Louisiana with only very limited exceptions in cases of risk to the mother's life or fetuses with fatal abnormalities.

Democrats believe abortion rights could be a key campaign issue in November's election, which is expected to pit President Joe Biden against Trump.

Trump told Time magazine in April he had "pretty strong views" on women's access to mifepristone and would share his opinions within a week of the interview, but never did so.

The conservative-majority Supreme Court heard an abortion pill case in March and appeared poised to reject restrictions imposed by a lower court on the drug.

A ruling in the case is expected by the end of June.