The White House could not immediately confirm reports that the Islamic State of Iraq and Syria has released a video showing the beheading of American journalist Steven Sotloff.

Speaking to reporters Tuesday afternoon during a regular briefing, White House press secretary Josh Earnest said he has not seen the reports of the video's release, but said if true, "our thoughts and prayers" are with the Sotloff family and his friends and colleagues.

"I've not seen those reports," he said. "This is something that the administration has been watching very carefully" since ISIS first threatened Sotloff's life in a previous video the group circulated of fellow American journalist James Foley's beheading two weeks ago.

"The U.S. have dedicated significant resources" to try to save Sotloff's life, Earnest said. "If there is a video that has been released, it will be analyzed carefully to determine its authenticity."