England captain Alastair Cook expects the reasons behind Kevin Pietersen's controversial axing to be made public soon.

The mystery surrounding the England and Wales Cricket Board's (ECB) decision to call time on Pietersen's international career has remained unanswered in the fall-out of the winter's 5-0 Ashes whitewash.

The ECB have suggested they are not yet in a position to reveal why Pietersen's glittering career was cut short - a position Cook reiterated on Tuesday.

Cook admitted it was "frustrating" not to be able to provide any clarity to the situation, which has hardly been aided by England's faltering fortunes on the field without their former talisman, although he suggested an answer may be forthcoming soon.

"I can't actually answer that question, totally, at this precise moment in time which is incredibly frustrating for me," he told Sky Sports News at Essex's media day.

"Everyone will say I'm sitting on the fence, but there are a number of reasons which will become clearer soon. You have to respect the decision and the position I am in at this precise moment in time.

"Everyone is going to keep asking that question until we give the answers, but at the moment we just can't so I'd love to talk about something slightly different."

In the wake of the ECB's decision - which was announced in February - there has been a public outcry for answers, most pointedly from high-profile media figure, and Pietersen ally, Piers Morgan.

Cook suggested those voices have hardly helped matters.

"It is frustrating," he said.

"If anyone thinks the decision was taken lightly and without a lot of consideration and a lot of thought - a lot of things went into the decision.

"It was a tough decision. The decisions will be made clearer in due course. You just have to respect that at the moment. It is frustrating. That is the position I'm in."

Pietersen's exit has come amid a raft of England changes post-Ashes as they look to rebuild a new era.

Team director Andy Flower also stepped down from his position and a decision on his replacement is set to be made in the coming weeks.

Limited overs coach Ashley Giles is the favourite to take over, although his reputation has not been aided by a difficult winter of his own, culminating in Monday's embarrassing 45-run defeat to minnows Holland at the World Twenty20.

England therefore crashed out out the tournament with just a single win, but Cook still has faith in Giles, who did lead the 50-over side to last year's Champions Trophy final.

"Gilo has had a tough winter - we've all had a tough winter," he said.

"He's a very, very good coach. He's a fantastic coach and a very good man as well. There are a lot of decisions to be made over the next couple of weeks by the hierarchy of the ECB - and important decisions as well."

Other reported candidates for the post includes former England coach Peter Moores - now at Lancashire - Mick Newell at Nottinghamshire and Australian Trevor Bayliss, who has coached Sri Lanka.

"I know there are a number of candidates as well," Cook said.

"I think we are lucky that we can choose from a good number of candidates. Gilo will certainly be in for that. I don't make the decision."

Cook is set to have some input, however, with Flower's coach-captain relationship with Andrew Strauss seen as an important part of England's rise to the top of world cricket.

"It is an important relationship and you do have an input," Cook added.

"The final decision is with the board, that is their job.

"You saw what a strong relationship Andy Flower and Andrew Strauss had together and how important it is. We're lucky with the candidates we have got and Ashley is one of the favourites. He knows the system well and I've enjoyed working with him,.

"Those decisions will come over the next couple of weeks. It's an exciting time for English cricket.

"It's a time when we have to look forward. It's been an incredibly tough winter in terms of what's happened and the way we've played our cricket. We can't hide away from that.

"There are a huge number of reasons to be optimistic. It will take time and hard work to turn it around.

"It took us three or four years to become the top-ranked Test side in the world under Flower and Strauss after we were bowled out for 51 in Jamaica.

"It is going to take time. It's going to take a lot of blood, sweat and tears to get there.

"Just chatting to the lads who are back in England after that experience in Australia. A lot of those guys are desperate to be a part of it and it is going to be tough. I'm very privileged to be a part of that and hopefully we can make the difference."