Poland's president on Tuesday insisted that Germany had failed to formally settle the issue of World War II reparations, amid moves by Warsaw's rightwing government to take stock of damages.
Germany has rejected Poland's claims, pointing to a 1953 decision by the country's then communist regime to relinquish demands for compensation.
"After 70 years this is still a political problem," President Andrzej Duda told the Catholic-nationalist TV Trwam and Radio Maryja stations.
While Duda acknowledged former West Germany's "gifts" and "kind treatment" for Poles during the "difficult period of communism", he insisted that the reparations issue remains "unresolved".
"We really didn't receive compensation," he added.
Duda and German President Frank-Walter Steinmeier agreed in September that a "calm discussion" was needed to address the delicate reparations issue.
Poland's powerful Roman Catholic church warned earlier that month that "poor decisions" by the EU country's rightwing leaders could "undermine" ties with Germany, after the Polish premier said Warsaw was "ready" to demand reparations.
Poland's nationalist Law and Justice (PiS) government disputes the validity of Warsaw's 1953 deal to relinquish World War II reparations, saying it was made under the diktat of the Soviet Union.
PiS lawmakers set up a parliamentary committee in September tasked with looking into the scale of reparations they claim Germany owes, but did not set a deadline to publish their findings.
Poland's foreign and interior ministers have estimated a potential bill reaching as high as $1 trillion (850 billion euros).
During World War II, Poland suffered the brunt of a two-front attack by Nazi Germany and the Soviet Union.
Six million Polish citizens, including three million of Jewish origin, were killed under the Nazi occupation of 1939-45, and Warsaw was virtually razed.
The issue of war reparations -- for years considered as settled -- was revived in July by Jaroslaw Kaczynski, the PiS's powerful party chief who is widely regarded as Poland's de facto leader.
The controversy comes as relations between Berlin and Warsaw have been strained over a slew of justice reforms introduced by the PiS since it took power in 2015.
German Chancellor Angela Merkel said in August that Berlin could "not stay silent" on EU fears about the rule of law in Poland, calling it a "serious issue".