COLUMBUS, Ohio -- Gov. John Kasich on Monday delayed nine executions as a court fight continues over the constitutionality of the state's lethal injection process, including a contested sedative used in problematic executions in at least three states.

Kasich's announcement postponed next month's execution of child killer Ronald Phillips until July and pushed back eight other procedures.

The Republican governor said the timing of arguments before a Cincinnati federal appeals court makes the delay necessary. The court is hearing Ohio's appeal of a federal judge's order finding the state's latest execution process unconstitutional.

Get Breaking News Delivered to Your Inbox

The effectiveness of the sedative midazolam is expected to be front and center of those arguments. That's especially true given last week's execution in Arkansas of Kenneth Williams, a convicted killer who lurched and convulsed 20 times during a lethal injection process Thursday that began with midazolam.

Midazolam was also used in Ohio in January 2014 when Dennis McGuire gasped and snorted during a 26-minute procedure, the state's longest. Executions in the state have been on hold since then.

In July 2014, Arizona inmate Joseph Wood gasped for air and snorted and his belly inflated and deflated during the time it took for him to die when the state executed him. His execution was supposed to take about 10 minutes, CBS News' Bill Whitaker reported for "60 Minutes." It took almost two hours.

In 1977 when lethal injections were introduced, they were supposed to be a more humane form of capital punishment, Whitaker reported. The process instead has become a testing ground for toxic, unproven drugs.

Both Ohio and Arizona used a two-drug method -- starting with midazolam -- that each state has since abandoned. Unlike Ohio, Arizona agreed not to use midazolam in future executions.

Attorneys for death row inmates challenging Ohio's use of midazolam say it doesn't render inmates fully unconscious, leading to an unconstitutionally high risk of harm.

The state argues that the massive dose planned in Ohio of 500 milligrams -- 10 times what it used on McGuire -- is more than enough to ensure inmates don't feel pain. The state also says the U.S. Supreme Court permitted the drug's use in a 2015 ruling out of Oklahoma.

Kasich issued a similar delay in February to give a three-judge panel of the appeals court time to hear similar arguments. That panel sided with the lower-court judge. In a rare move, the full court said it would hear the case and set arguments for June 14.

Monday's delay was another setback for death penalty supporters who hoped that new supplies of drugs obtained by Ohio last year would allow executions to move forward after a delay of more than three years.

The state has said it has enough drugs for four executions, but records obtained by the Associated Press indicate Ohio could have enough on hand to put dozens of killers to death.

Phillips, scheduled to die May 10 for raping and killing his girlfriend's 3-year-old daughter in Akron in 1993, is now set for execution July 26.