Tweets from ISIS supporters indicate today is the deadline for the Obama administration to halt the bombing campaign in Iraq or U.S. captive Abdul-Rahman Kassig will be killed.
A tweet from Twitter user @saadAlaqidy states: "Wednesday is the last day of the time limit set by #Ath_alasalamah related Balazer has "American Soldier #Kaseg_petr."
The former Butler University student and Army Ranger has been held captive for more than a year.
His family has used Twitter to issue appeals for his release.