Professor Wladyslaw Bartoszewski, former foreign minister and currently an aide to Polish Prime Minister Donald Tusk, said Poland should "fix all that was spoiled" by former Prime Minister Jaroslaw Kaczynski in the past two years, Polish Radio reported.

Bartoszewski said the Kaczynski government had "consciously worsened" Polish-German relations. He told Poland's TVN-24 television that ice on the two countries' relations should be defrosted.

Among outstanding issues was Kaczynski's claim Poland should be given bigger voting rights in the European Union to make up for 6 million Poles killed by the Nazis during World War II. Had Poland not suffered such a loss, its population would have been larger and therefore its voting rights bigger, Kaczynski said.

Other issues are related to claims by individual Germans seeking property they left in Poland when they were expelled from Polish territory after World War II, and a plan by Germany and Russia to build a gas pipeline under the Baltic Sea to bypass Poland.