The Argentinian striker clinched the Blues' first title triumph since 1968 with a dramatic injury-time winner in the final game of last season, but City trail local rivals Man United by 12 points with 11 games remaining.
"Can we still win the title? I'd like to believe so," declared the 24-year-old former Atletico Madrid star.
"We can't give up, even though it looks tough."
City have progressed to the quarter-finals of the FA Cup, where they face a home date with Barnsley, and Aguero hopes that their form in knock-out games can inspire a late bid for the title.
"Let's take it step by step," he added. "Take the FA Cup, each victory means we are a step closer to winning the competition.
"It's about keeping focused and trusting in our game. That applies to all our remaining Premier League games too."