On Friday, a federal US court denied John Demjanjuk's latest bid to block his extradition to face charges of aiding in the wartime murder of 29,000 Jews.
“Based on the medical information before the court ... the court cannot find that the petitioner's removal to Germany is likely to cause irreparable harm sufficient to warrant a stay of removal," the appeals court ruled.
“His motion for a stay of removal pending review is denied.”
A spokeswoman for the Justice Department declined to comment on when the 89-year-old retired autoworker would be deported but said "the US government will continue to seek the removal of Mr Demjanjuk to Germany."
Demjanjuk's son said the family was considering an appeal to the US Supreme Court and had also filed a lawsuit in Germany seeking an emergency stay.
“Given the history of this case and no evidence of his personal involvement in even one assault, let alone a murder, this is inhuman, even if a court says it is lawful," the son, also called John Demjanjuk, said in an e-mail.
The decision is the latest development in a decades-long saga over his father's wartime actions.
In a dramatic twist last month, the octogenarian won an 11th-hour reprieve when the court stayed his deportation shortly after he was carried out of his suburban Cleveland, Ohio home in a wheelchair to be put on a flight to Munich.
But on Friday, the appeals court rejected an argument by Demjanjuk's lawyer that his client is in such poor health that jailing and trying him in Germany would cause him pain amounting to torture.
"At most, he has offered speculation that German authorities may not adequately attend to his medical needs while he is in that country's custody," the court ruled.
Born in Ukraine in 1920, Demjanjuk was a soldier in the Red Army when he was captured by the Nazis in the spring of 1942.
He was trained at Treblinka in Nazi-occupied Poland and served two years in the camps of Sobibor and Majdanek, also in occupied Poland, and in Flossenburg in Bavaria.
Demjanjuk has always insisted that he was forced to work for the Nazis and had been mistaken by survivors for other cruel guards.
He immigrated to the United States in 1952 with his family, settling in Ohio, where he found work in the auto industry and changed his name from Ivan to John.
An Israeli court condemned him to death in Israel in 1988 after convicting him of being the sadistic Nazi guard nicknamed "Ivan the Terrible," but the verdict was later overturned by the Israeli Supreme Court because of doubts about his identity.
He was returned to the United States over strenuous objections from Holocaust survivors and Jewish groups, who argued there was sufficient evidence that he served as a death camp guard to warrant another trial.
Demjanjuk regained his US citizenship, which had been first stripped in 1981, after an appeals court ruled in 1998 the US government recklessly withheld exculpatory evidence.
In 1999, the US government filed new charges using fresh evidence that surfaced following the collapse of the Soviet Union, and he was again stripped of his US citizenship in 2002.
Germany issued a warrant for Demjanjuk's arrest on March 11 on charges of assisting in the murder of 29,000 Jews.