Greek President Karolos Papoulias on Tuesday stressed the importance of remembering Nazi war crimes during a visit to the site of Auschwitz, Nazi Germany’s largest concentration camp in southern Poland.

“I am here to pay my respects to the thousands of victims of Nazi atrocities, including thousands of my fellow citizens,” Papoulias wrote in the visitors’ book.

In a statement after signing the book, Papoulias said, “It is the duty of us all to ensure our memories of the tragic historic fact of Nazi barbarism do not become rusty.”