Poland has estimated the financial cost of World War II losses to be 1.3 trillion euros and says it will "ask Germany to negotiate these reparations".
"It is a major sum of 6.2 trillion (Polish) zloty," said Jaroslaw Kaczynski, head of the ruling Law and Justice party (PiS), adding that receiving reparations would be a "long and difficult" process.
Kaczynski was speaking at a conference dedicated to the presentation of a report on Poland's losses in the 1939-1945 war.
"The Germans invaded Poland and did us enormous damage. The occupation was unbelievably criminal, unbelievably cruel and caused effects that in many cases continue to this day," he said.
The invasion of Poland (1 September – 6 October 1939) was a joint attack on the Republic of Poland by Nazi Germany and the Soviet Union which marked the beginning of World War II.
Britain and France declared war on Germany on 3 September.
Since coming to power in 2015, the PiS party has often championed the issue of war reparations.
According to the website of the PiS, work on the reparations report began in 2017, when the conservative government insisted that Germany had a "moral duty" in the matter.
Germany has often rejected Poland's claims, pointing to a 1953 decision by Poland to reject reparation claims against East Germany.
On Thursday, Kaczynski brought the issue back front and centre.
"We have not only prepared a report... but we have also taken a decision, a decision on further action," Kaczynski said.
"That action is to ask Germany to negotiate these reparations. And this is a decision that we will implement."