Yasuhisa Arai concedes Honda felt the effects of their absence from racing last season but insists they will resolve their technical problems this year.
Honda returned to Formula 1 with McLaren in 2015 but the partnership failed to replicate the success of the 1980s.
Instead Jenson Button and Fernando Alonso struggled to reach Q2 in qualifying while the chequered flag was often a step too far on Sunday afternoons.
The duo managed just 27 points putting McLaren-Honda down in ninth place in the Constructors' Championship.
Asked what went wrong, Arai told the Nikkei Asian Review: "The season was really tough and we failed to meet expectations placed on us by fans, McLaren and those who provided support to us. There are many reasons for that, but I think the results say everything.
"Early in the season, we felt the effects of our seven-year absence from racing. We anticipated technological troubles. And although we recognised them, we failed to quickly pinpoint the causes, come up with measures to resolve them and make the necessary adjustments. We were suffering from what athletes call a "lack of match sharpness."
"We participated in our first race of the 2015 season, the Australian Grand Prix, in March last year before mastering the complicated hybrid system (required under current F1 regulations). We all did our best, but a lot of technological troubles occurred before we could capitalise on our collective experience. We got off to a really difficult start."
He does, however, believe that Honda will do better this season as they seek to resolve the reliability issues that plagued them in 2015.
He said: "We're keen to meet everyone's expectations and reach the podium as soon as possible. We will resolve the technological problems we failed to address in 2015 and will head into the opening race with confidence."