The Polish Foreign Minister Zbigniew Rau has signed a diplomatic note to Germany concerning reparations for World War Two, he said on Monday, formalizing Poland's demand for compensation.
The move comes after Poland's ruling nationalists last month estimated Germany owed the country 6.2 trillion zlotys ($1.26 trillion). Germany, Poland's biggest trade partner, has said all financial claims linked to the war had been settled.
"(The note) expresses the position of the Polish minister of foreign affairs that the parties should take immediate steps to permanently and effectively... settle the issue of the consequences of aggression and German occupation," Zbigniew Rau told a news conference.
Some six million Poles, including three million Polish Jews, were killed during the war and Warsaw was razed to the ground following a 1944 uprising in which about 200,000 civilians died.
In 1953, Poland's then-communist rulers relinquished all claims to war reparations under pressure from the Soviet Union, which wanted to free East Germany, also a Soviet satellite, from any liabilities.
Poland's ruling nationalists Law and Justice (PiS) say that agreement is invalid because Poland was unable to negotiate fair compensation. It has revived calls for compensation since it took power in 2015 and has made the promotion of Poland's wartime victimhood a central plank of its appeal to nationalism.
The combative stance towards Germany, often used by PiS to mobilize its constituency, has strained relations with Berlin.
The German foreign ministry did not immediately reply to an emailed request for comment.