KP has also been left out for the upcoming four one-day internationals against South Africa starting Friday.
London: Defending champion England left Kevin Pietersen out of its squad on Tuesday for the World Twenty20 in Sri Lanka next month, leaving the batsman's future with the national team unresolved.
Pietersen was dropped for England's final test against South Africa after admitting sending "provocative" text messages to members of the opposition.
"He played superbly in our last Twenty20 World Cup, but the circumstances that exist at the moment mean that he can't be selected for us," England team director Andy Flower told Sky Sports television.
"There are still issues unresolved and we will be addressing those issues when we have time to do so ... those issues have to be resolved before there is any way forward."
Pietersen was awarded the player of the tournament as England won the T20 world title in 2010.
"This is not just an issue between the captain and Kevin," captain Andrew Strauss said. "There are deeper issues. Certainly the issues of trust and mutual respect need to be addressed. There are unresolved issues that have reared their heads in the last few weeks."
Pietersen was also left out of the four one-day internationals against South Africa, which start Friday.
Twenty20 squad: Stuart Broad (capt), Jonny Bairstow, Ravi Bopara, Tim Bresnan, Danny Briggs, Jos Buttler, Jade Dernbach, Steven Finn, Alex Hales, Craig Kieswetter, Michael Lumb, Eoin Morgan, Samit Patel, Graeme Swann, Luke Wright.
ODI squad: Alastair Cook (capt), James Anderson, Jonny Bairstow, Ian Bell, Ravi Bopara, Tim Bresnan, Jade Dernbach, Steven Finn, Craig Kieswetter, Eoin Morgan, Samit Patel, Graeme Swann, Jonathan Trott, Chris Woakes.