Manchester United stretched their lead at the top of the Premier League to seven points with a home win over Newcastle but Hart believes the situation is far from terminal.
"We've had leads, United have had the lead - it's to-ing and fro-ing at the moment," he declared to City's website.
"We're a team of winners, it's hard and it hurts but we've got to move on. It is hard to lead and it is hard to chasse too.
"We've clawed points back before, we proved it at the end of last year - we've just got to believe."