Oklahoma plans to use nitrogen gas to execute inmates once the US state resumes using the death penalty, marking the first time a state would use the gas to carry out capital punishment.
State attorney general Mike Hunter and corrections director Joe Allbaugh made the announcement today.
Oklahoma and other states have not been able to get the drugs required for lethal injections amid opposition from drugmakers to having their products used in executions.
Oklahoma has had one of the busiest death chambers in the US, but has not carried out an execution since 2015 after a series of mishaps, including a botched lethal injection in 2014 that left an inmate writhing on the gurney.
Mr Hunter said using nitrogen is the best way for Oklahoma to resume executions.