US President Barack Obama will attend the funeral of his Polish counterpart Lech Kaczynski, killed in an air crash in western Russia on Saturday. The presidents of Russia and France, Dmitry Medvedev and Nicolas Sarkozy, are also due to attend the funeral in the city of Krakow on Sunday. Mr Kaczynski and his wife Maria will be buried in a crypt close to historic Polish leader Jozef Pilsudski. The date of the next presidential election is to be announced shortly.