President Barack Obama promised a better debate performance when he faces Mitt Romney again next week, in an interview with ABC News' Diane Sawyer Wednesday night. He also said Romney’s “sales pitch” conceals his true views.

"Governor Romney had a good night. I had a bad night. It's not the first time," Obama said in his first televised interview since the Oct. 3 Denver debate that has damaged his candidacy. Despite Romney's post-debate momentum and surge in the polls, the "fundamentals of what this race is about haven't changed," he said.

"This was one event. We've got four weeks to go. Nobody is going to be fighting harder than I am," Obama told Sawyer, aiming to reassure his nervous supporters. "What they need is to make sure they tune in on Tuesday next week."

"If you have a bad game you just move on, you look forward to the next one, and it makes you that much more determined," he said.

Asked by Sawyer whether it's possible that his poor showing had handed Romney the election, Obama replied, "no."

"You're going to win?" she asked.

"Yes," Obama said.

"You want it more than the first time?" she pressed, noting that some Democrats have questioned his energy and will to win.

"Absolutely," he said.

The president indicated that he is preparing to more aggressively counter Romney's "sales pitch" when they meet again at Hofstra University in New York next Tuesday.

"What he spent most of his time doing was hiding the ideas that he's been running on for the last year and that the American people had essentially rejected," Obama said. "And so they desperately tried to cover up what exactly they've been proposing."