(CNN) -- Radical militant Islamist websites posted a new video Friday containing an audio message purported to be by Humam Al Balawi, the Jordanian doctor turned suicide bomber who killed seven CIA agents in eastern Afghanistan in December.
The audio message, which was produced by as-Sahab, al Qaeda's media arm, is played over a picture of Al-Balawi and English subtitles with on-screen text that reads: "A message that was delivered on the night before his martyrdom operation against the American intelligence in Khost."
For nearly 30 minutes, the speaker in the message makes various arguments addressing those who are "undecided" and "hesitant" to join the armed fight, or jihad, against Western forces in Muslim lands.
In the message titled "O Hesitant One, It Is An Obligation," the speaker talks about "heroic stories," sometimes using personal references such as, "I lived among you for such a long time." In other passages, he speaks to those who may have "hidden" love for jihad. Near the end of his message, the speaker challenges those "undecided brothers" by appealing to their "manhood and chivalry."
"We shall send you coded messages" through media outlets to continue the call for jihad, he said.
The message was alleged to have been recorded on December 29, 2009. Al-Balawi struck the U.S. base the following day.