Demjanjuk said he was "forcibly deported to Germany" where "false charges" were pressed on him, in a statement read out to a court in Munich by his lawyer, Ulrich Busch, and obtained by AFP.
"I find it an unbearable injustice that Germany is trying to make me, a prisoner of war, into a war criminal with this trial," the statement said. "I am grateful to my medical staff who have helped to reduce the worst pain and allowed me to get through this trial which I feel is torture," said the native Ukrainian, who has lain motionless on a stretcher for most of the trial.
Demjanjuk's family say he is suffering from a litany of health complaints and will likely not survive the trial.
Doctors have judged him fit to stand trial but limited the time he is in court. Several sessions have been postponed after Demjanjuk complained of pain or dizziness.
Demjanjuk is accused of spending six months in 1943 at the Sobibor death camp in Nazi-occupied Poland, pushing thousands of Jews into gas chambers. He has always denied the charges.
He was previously found guilty in Israel of being "Ivan the Terrible," a particularly sadistic death camp guard at Treblinka, but released after the Israeli Supreme Court established they had the wrong man.
In his statement, Demjanjuk said he had been "falsely prosecuted" for the past 30 years in Israel, in Germany and in the United States, where he lived before being deported to the southern city of Munich to stand trial.
"Germany is to blame for the fact that I have lost my whole reason for living, my family, my happiness, and any future or hope," he said. "Now, at the end of my life, I am going through the 30th or 40th trial dealing with the same issue and I no longer have the strength to resist ... Germany is to blame for the fact that I have led a miserable life."