The US Supreme Court rejected two appeals for death row inmate Marcus Wellons, clearing the path for his execution in what would be the first since a botched lethal injection.
Wellons, convicted of the 1989 kidnapping, rape and murder of a 15-year-old girl, had been scheduled to be put to death earlier Tuesday in Georgia, a spokesman said, adding that the lethal injection remained set for that night.
If no 11th hour appeal stops it, the execution will be the first since one in Oklahoma on April 29 left a death-row inmate writhing in pain. Each execution slated to take place since has been delayed.
Wellons is on death row in Georgia for killing and raping a 15-year-old girl he snatched on her way to school.
In the second case, John Winfield, convicted of killing two women, had been due to be put to death at 12:00 am Wednesday (0500 GMT) in Missouri. The top court has until the end of the day Wednesday to rule in that appeal.
A third execution is also scheduled for 6:00 pm (2200 GMT) Wednesday in the southern state of Florida.
US states using the death penalty have faced crisis over shortages of lethal injection drugs after European suppliers stopped supplying pentobarbital for use in executions.
The shortages have prompted prison departments in the 32 states that still allow the death penalty to seek new supply sources or new drug protocols.
In Oklahoma, Clayton Lockett, a convicted killer and rapist, was put to death by lethal injection in a process that took 43 minutes, well over the expected time of a little over 10 minutes.