Kurt Volker resigns as US special envoy to Ukraine

New of his resignation was first reported by the State Press at ASU.

Kurt Volker has resigned as U.S. special envoy to Ukraine, a source familiar has told ABC News.

News of Volker's resignation was first reported by The State Press, the student newspaper at Arizona State University.

Democrats still are expecting Volker to show up for his deposition on Capitol Hill on Oct. 3, sources tell ABC News.

This is a breaking story. Please check back for updates.