Former Gov. Ed Rendell thinks U.S. Sen. Elizabeth Warren, who some Democrats had hoped would run for president, is not even qualified to be Hillary Clinton's pick for vice president.

Speaking on Rich Zeoli's show on 1210 WPHT on Wednesday, Rendell said Warren is "not in any way, shape, or form ready to be commander-in-chief."

Rendell later called back to temper his assessment.

"I didn't want to leave it hanging out there about Elizabeth Warren," he said, adding that he liked her.

"Elizabeth Warren's problem would be the same problem I'd have. I mean, let's assume someone said, consider Gov. Rendell for vice president. I have no experience militarily, no experience in foreign affairs, and would be a difficult choice because if anything happened in week one and I became president, I would be lost," Rendell said. "I think Elizabeth Warren, four years from now, would be a great choice to be on the ticket."

Warren took office in January 2013 as a senator representing Massachusetts. With a background in economic affairs and consumer protection, she served high-profile roles in the recovery following the 2008 financial crisis.

Rendell is chair of next month's Democratic National Convention in Philadelphia.