"We now have won primaries and caucuses in 19 states," Sanders said at a rally in Salem, Oregon Tuesday evening. "Let me be as clear as I can be. We are in this campaign to win the Democratic nomination."

Sanders acknowledged, however that he faces an uphill climb. And he added a subtle hint that he would seek to unite the party in a general election if he fails to win the nomination.

"While we have many disagreements with Secretary Clinton, there is one area where we agree and that is we must defeat Donald Trump."