Gerhard Schroeder will be the first German chancellor to attend the annual ceremonies [of the Warsaw Uprising] when he visits on Sunday.
Poland's prime minister called on him to dismiss calls for reparations from ethnic Germans driven out of Poland at the end of World War II.
Prime Minister Marek Belka told Germany's Die Welt newspaper that Mr Schroeder's visit was of "huge importance" to Poland.
He said there was a "bad atmosphere" between their two countries, and urged his German counterpart to dispel it.
Mr Belka said it would send a powerful message if Mr Schroeder used the anniversary to speak out against reparation claims by Germans expelled from Poland.
"The bigger and stronger neighbour must always show greater sensitivity," he said.
Mr Belka said he did not suggest the chancellor should drop to his knees - as his predecessor Willy Brandt did in 1970 in a gesture of humility at the site of the 1943 Jewish rebellion in the Warsaw ghetto.
"We do not expect him to kneel but we expect good words," he said.