CNN showed footage of the president and his advisers wearing the mask at the Walter Reed Army Medical Centre in Washington.
"I'll probably have a mask if you must know. I'll probably have a mask. I think when you're in a hospital especially in that particular setting, where you are talking to a lot of soldiers, people that in some cases just got off the operating table. I think it's a great thing to wear a mask. I've never been against masks but I do believe they have a time and a place," he told reporters.