NEW : The EU `` calls for the early appointment of a successor '' for Annan . In an interview with BBC Radio 4 today, Mr Blair said he was not aware that any such plan had been drawn up. U.S . Ambassador : Security Council vetoes made Annan 's mission impossible .
NEW : The EU `` calls for the early appointment of a successor '' for Annan . U.N. Secretary-General Ban Ki-moon announced the move with `` deep regret '' Arab League Secretary-General Nabil El Araby and Ban are looking for a successor . U.S . Ambassador : Security Council vetoes made Annan 's mission impossible .