"The secretary-general condemns in the strongest terms the horrific murder of journalist James Foley, an abominable crime that underscores the campaign of terror the Islamic State of Iraq and the Levant (ISIL) (now called Islamic State) continues to wage against the people of Iraq and Syria," Xiinhua quoted a statement issued here by Ban's spokesperson as saying.
"The perpetrators of this and other such horrific crimes must be brought to justice," Ban stressed.
The UN chief also extended his deepest condolences to the family, friends and colleagues of Foley.
A video released by the IS militants Tuesday purported to show the beheading of Foley and contained threats to kill the other in retaliation against the recent US intervention in Iraq.
A masked fighter was shown beheading a man kneeling in an orange jumpsuit said to be Foley, a 40-year-old freelance journalist who disappeared in northwest Syria in 2012.
Earlier Wednesday, the White House said that the video showing the beheading of Foley had been authenticated by the US intelligence community.