The Islamic State group has released a video in which they claim to show the beheading of an American journalist.
The militants say the killing of James Foley - who was abducted in Syria in 2012 - is in revenge for American airstrikes against I.S. in Iraq.
They say the life of another kidnapped journalist in the video depends on the US President Barack Obama's "next decision".
US officials are checking to see if the footage is real.
This is a clip from a masked man in the message, who has a British accent;
The mother of James Foley posted a heartfelt message on Facebook;
"We have never been prouder of our son Jim. He gave his life trying to expose the world to the suffering of the Syrian people.
We implore the kidnappers to spare the lives of the remaining hostages. Like Jim, they are innocents. They have no control over American government policy in Iraq, Syria or anywhere in the world.
We thank Jim for all the joy he gave us. He was an extraordinary son, brother, journalist and person. Please respect our privacy in the days ahead as we mourn and cherish Jim."
