England Test captain Alastair Cook has refused to indicate whether talks between the ECB and Kevin Pietersen have been successful.

The two parties are believed to be negotiating the possibility of Pietersen's return to the Test squad after the batsman was dropped for sending derogatory texts to South African players about former skipper Andrew Strauss.

"I cannot say anything," Cook told the Evening Standard. "At this precise moment, stuff is going on behind closed doors with respect to both sides so that we can get the best possible outcome."

Cook, who replaced Strauss as captain last month, has admitted that the Test series loss against South Africa proved that they were not comfortable being labelled the best side in the world.

"We had an amazing run as a Test team but, for whatever reason, when we became number one we never played to that standard again. I do not know why. Maybe there was a psychological problem. Maybe being the number one side did not sit as comfortably with us as we thought it would," he added.

Cook has not been included in the squad to compete in the Twenty20 World Cup, beginning later this month in Sri Lanka.