In a note to the media, Ban said he shares the sorrow of the family and loved ones of Moaz al-Kasasbeh, the pilot of the Jordanian Royal Air Force, and stands in solidarity with the people of Jordan in denouncing this "appalling" act.

Ban also urged all government of all countries across the world to strengthen their efforts to combat the scourge of terrorism and extremism within the bounds of their human rights obligations, according to the note.

Al-Kasasbeh was captured after his plane crashed in December. Since then, he has become a main pawn for IS. The Jordanian government had expressed readiness to conduct a prisoner swap with IS in exchange for the safe release of al-Kasasbeh and Japanese journalist Kenji Goto. But the deadline for the swap expired on January 29 as Jordan demanded proof from the IS militants that al-Kasasbeh was still alive.

The video of al-Kasasbeh's purported death came just days after the IS militants beheaded the Japanese journalist. The Jordanian government said it confirmed the man burned to death was al- Kasasbeh and the killing took place on January 3, far earlier than the prisoner swap proposed by IS.

Latest News from World News Desk