Kevin Pietersen 'determined to regain' Ashes for England

England's Kevin Pietersen says he is "determined to help regain the Ashes" when they next play Australia in 2015.

Pietersen also wrote on Twitter:  "Very disappointed to lose 5-0, and not to score more runs personally. Tough tour against a top-class team."

The 33-year-old batsman was England's top scorer in the recent Ashes series - with 294 runs at an average of 29.

But his Test future has been questioned  by pundits including former England captain Geoffrey Boycott.

"When it comes to batting with patience and concentration against disciplined bowling, he just can't do it," said Boycott, who scored 8,114 runs in 108 Tests at an average of 47.72, during England's third Test defeat in Perth. "He bottles it."

But Boycott's Test Match special colleague Michael Vaughan, who was Pietersen's England skipper, believes he should be made vice-captain.

"He is England's best player," said Vaughan. "He can make the biggest impact on the game but he is not involved in this team. If there's an issue there, get rid of him. If not, then involve him."

Before the latest Ashes series, in which Australia regained the Ashes, Pietersen said he wanted to continue playing for England until at least the 2015-16 tour of his native South Africa.

"As long as the body goes well, I'm good for it," Pietersen, who made his international debut in 2004 and has starred in four Ashes series wins, told BBC Sport in November.