Vermont Sen. Bernie Sanders promised to keep campaigning nationwide to spread his message — including in conservative states.

"I will be able to deliver in Washington; I will be able to win the election," the Independent, who is running for the 2016 Democratic presidential nomination, said on CBS Sunday. "The message that we have is resonating."

Sanders pledged to campaign in Alabama, Mississippi and other red states. However, "electing Bernie Sanders as president" is not enough. "We need a mass grassroots movement in this country," he added.

Sanders also contrasted himself with Democratic front-runner Hillary Clinton. Clinton is expected to announce her economic vision Monday.

"I voted against the war in Iraq," Sanders said, while the former secretary of state, he noted, "voted for the war." He also said that while he's worked to kill the Keystone XL pipeline, Clinton's view on the issue "hasn't been clear."

And, he added, he believes that if a "bank is too big to fail, it's too big to exist. Money cannot be the god of life."

Sanders, once considered a long-shot candidate, is now challenging Clinton in many states. At a rally in Wisconsin earlier this month, he drew a crowd of nearly 10,000 — the biggest crowd of any 2016 candidate yet.