A federal agency has warned Ohio that the state would be breaking the law if it carried out plans to import lethal injection drugs from overseas.

The U.S. Food and Drug Administration informed Ohio prisons director Gary Mohr of its legal concern in a June letter, released Wednesday after BuzzFeed reported on the letter.

The communication followed Ohio's announcement that it intended to obtain supplies of thiopental sodium to replace a two-drug combination it halted after a troubled 26-minute execution in 2014.

Thiopental sodium is no longer available in the U.S. and overseas imports are subject to importing bans.

Ohio prisons spokeswoman JoEllen Smith says the state continues to seek all legal means to obtain the drugs necessary to carry out court-ordered executions.