Hillary Clinton’s campaign manager Sunday charged Donald Trump with potentially being a “puppet” of the Kremlin and demanded that the Republican presidential nominee disclose whether members of his campaign are conducting meetings with Russian officials.

“Paul Manafort has been pushed out, but that doesn’t mean that the Russians have been pushed out of this campaign,” Robby Mook told ABC’s George Stephanopoulos. Mook was referring to the recent departure of Trump’s campaign manager, whose consulting firm is now being investigated by the FBI and Justice Department for possible ties to corruption involving ousted Ukrainian President Viktor Yanukovych.