De Boer rues missed chance
Siem de Jong netted twice in the opening 20 minutes to gift the Dutch side a 2-0 lead, but Yaya Toure pegged one back for City before the break, with Sergio Aguero eventually restoring parity after the interval.
De Boer said that given his side had pulled ahead so early in the match, they felt an opportunity had been missed to secure three vital points away from home.
"Before the match started, we would have taken a 2-2 draw here. But after the match I have the feeling that the players were actually disappointed with the result," De Boer told reporters.
"We could have delivered a hammer knockout blow to City. It is a good sign that the players were disappointed with this result. We could have taken a giant step tonight.
"That they scored their second goal out of nothing was very disappointing for us. But you know when you play here, it will get tough."
Ajax take on Borussia Dortmund in their next Champions League match, and De Boer has not given up on making it to the knockout stages.
"We aim to stay in the Champions League, and although Dortmund are very strong, we proved over there that we are capable of playing good football," he said.
Ajax sit third in Group D, trailing leaders Dortmund by four points with two games to go.