In fact, Clooney, 55, heard news of the split through the media. At Tuesday's Leaders Summit for Refugees at the United Nations General Assembly in New York, the actor was asked by a CNN reporter to comment on Jolie and Pitt's breakup.
"What happened?" Clooney said, clearly taken aback. "I didn't know that. I feel very sorry then. That's a sad story and unfortunate for a family. It's an unfortunate story about a family. I feel very sorry to hear that."
Clooney and Pitt, 52, share a friendship that spans over a decade. They've shared the big screen in the Ocean's trilogy from 2001 - 2007 and then costarred in 2008's Burn After Reading.
Angelina Jolie, Brad Pitt and George Clooney
Jolie, 41, filed divorce papers on Monday, noting in court documents that she and Pitt have been separated since Sept. 15. Jolie cited irreconcilable differences for their split, and did not request child or spousal support for their six kids.
"I am very saddened by this, but what matters most now is the well-being of our kids," Pitt said in the statement to PEOPLE. "I kindly ask the press to give them the space they deserve during this challenging time."