“I would love to have those extended over a period of multiple months and years, but that’s not the circumstances that I find myself in,” said Mr. Hutchinson, who took office in 2015. “And, again, the families of the victims that have endured this for so many years deserve a conclusion to it.”

In a statement on Friday, Mr. Hutchinson said that it was necessary to schedule the executions close together because of doubts about the future availability of one of three drugs the state uses in its lethal-injection procedure. State officials have previously said that the expiration date would pass in April for Arkansas’s supply of midazolam, a drug that has been used in several botched and gruesome lethal injections in other states in recent years.

Amid the controversy generated by such cases, a number of pharmaceutical companies have restricted their drugs from use for capital punishment. Some states have had difficultly finding midazolam. Arizona announced last year it would stop using it in part because of the logistical challenges.

“It is uncertain as to whether another drug can be obtained,” Mr. Hutchinson said in the statement, “and the families of the victims do not need to live with continued uncertainty after decades of review.”

This week, the governor signed proclamations setting four execution dates for the eight inmates between April 17 and 27. Two men would be put to death on each of the four dates. If Arkansas follows that timetable, it will be at a rate unmatched by any state since the United States resumed the death penalty in 1977, according to the Death Penalty Information Center, a nonprofit research group that opposes capital punishment.