Vice President Biden privately met with Massachusetts Sen. Elizabeth Warren on Saturday to sound her out for support of his possible Democratic White House bid, CNN reported.

Warren, who has not endorsed a candidate in the primary, met Biden at the Naval Observatory in Washington, DC, at his request, the report said.

Biden is quietly exploring a presidential run as Hillary Rodham Clinton’s campaign has sputtered through the summer.

He has told confidants he intends to make a decision in the next month, according to reports.

The first Democratic debate is Oct. 13.