(Reuters) - Alberto Zaccheroni said he would take some time before deciding whether or not to continue as Japan coach after their World Cup journey ended with a thumping 4-1 defeat by Colombia.

The Italian, who has been in charge for four years and led them to the 2011 Asian Cup title, said he had enjoyed his time in charge but admitted his side had failed to perform during their winless run in Brazil.

"I will speak to the management and will let you know whether or not I will stay. I think it is only appropriate for this question to be discussed within the team first," Zaccheroni told reporters.

"I think we left quite a lot to be desired in the first two games. We picked up in the third match. We were forced to play everything against a team that has great potential to go very far in this tournament.

"We all thought we would do a lot better, that we would perform much better as we showed in the first half (against Colombia) when we play intensely as we normally do and we are able to generate opportunities to win a match."

Shinji Okazaki's header on the stroke of halftime on Tuesday put the Japanese level but the South Americans, who had made wholesale changes for the match, brought on James Rodriguez at the break and he took control at the start of the second period.

Japan were unable to cope with the lightning quick counter-attacks of the Colombians.

Zaccheroni said the damage had been done in throwing away a 1-0 lead against Ivory Coast to lose their opening Group C clash 2-1 and failing to break down 10-man Greece in a goalless stalemate.

"Unfortunately, what I will take back in my mind is the fact that in the first two matches we failed to play the game we normally play," he bemoaned.

"For sure this team could have done a lot, lot more. I am certain that here in Brazil with me, I bought a great squad that could have done a lot more. And as a coach, I take my responsibility."

The 61-year-old former AC Milan, Inter and Juventus coach admitted his surprise at the team's failings but struggled to pick a reason for the fault as questions flowed about his team's defensive issues and the players' mental and physical strength.

"It's difficult to pinpoint a single reason when you get the approach wrong," he added. "I don't know. We were all surprised, the management, the squad, it is a doubt that will remain within me.

With or without Zaccheroni, Japan will defend their Asian Cup title in Australia in January.