WARSAW, Poland — Poland’s president has warned that Europe must learn lessons from World War II and must not tolerate any return to imperialist land grabs, an apparent reference to Russia’s annexation of Ukraine’s region of Crimea.

Andrzej Duda was speaking Thursday at a ceremony marking the 77th anniversary of the start of World War II. He made his remarks on the Westerplatte peninsula in Gdansk on Poland’s Baltic coast, where some of the war’s first shots were fired at 4.45 a.m. on Sept. 1, 1939. There, a Polish army outpost held out for a week against German naval and air attacks.

“We cannot allow imperial ambitions and actions to return to Europe. … We cannot shut our eyes when international laws are violated … or when borders in Europe are moved by force,” Duda said.

In a separate ceremony on Wednesday, one of Poland’s oldest war veterans, Lt. Jozef Zurek, was awarded a medal and a saber on his 107th birthday.

Zurek fought invading Nazi Germans in a battle on the Bzura River in September 1939 where he was taken prisoner and then sent to forced labor in Germany. He returned in 1946 to his home village of Czarnowo, in central Poland.

In the ceremony in Czarnowo, Zurek received a “Pro Patria” (“For the Motherland”) medal and a traditional officer’s sabre from the state Office of War Veterans and Victims of Oppression.