The US government met an Ohio court deadline to provide documents from a doctor stating that John Demjanjuk was well enough to fly to Germany and pledging that he would travel comfortably and with medical care.
"For all the foregoing reasons, this court should dismiss (the) petitioner's motion for stay of removal," the Justice Department said.
The move was the latest in a lengthy decades-long saga during which Demjanjuk has fought to avoid deportation to Germany where he is wanted on charges of aiding the killings of some 29,000 Jews during World War II.
In a dramatic twist earlier this month, Demjanjuk won an 11th-hour reprieve when the court stayed his deportation shortly after he was carried out of his Cleveland, Ohio, home in a wheelchair to be put on a flight to Munich.
Demjanjuk's lawyer has argued his client is in poor health, and that jailing and trying him in Germany would cause him pain amounting to torture.
His family says he is bedridden and suffers from a host of ailments including kidney disease, arthritis and cancer which makes him unfit to fly.
But the Justice Department argued: "None of the medical reports submitted by the petitioner support his claims that his physical condition would subject him to torture if transported or incarcerated."
It submitted a confidential report by flight surgeon Captain Carlos Quinones certifying that Demjanjuk had been cleared to fly after an examination.
It also sent the court four videos said to show the 89-year-old getting out of his car and entering medical offices.
The Justice Department also dismissed Demjanjuk's claim that sending him for trial to Germany amounted to torture, and said it was in the public interest that he be tried. Germany issued a warrant for Demjanjuk's arrest on March 11.
Demjanjuk had failed to "provide any evidence that he would suffer torture upon removal to Germany," the department said in its filing. "Rather he relies merely upon his own alleged subjective fear of physical and psychological suffering and discomfort due to the ailments of old age and prior legal proceedings against him."
When Demjanjuk was scheduled to be extradited on April 14, US immigration agents were to fly him out "on a Gulfstream chartered jet equipped with a bed and linens for reclining and accompanied by medical personnel," the Justice Department said.
US officials intend "to use the same or a similar chartered aircraft" to send him to Germany, the department said.
Demjanjuk's son has accused the Justice Department of withholding evidence about his father's health from courts in Germany and the United States of "creating the false impression that my father is 'stable' enough for travel and legal proceedings in Germany."
Born in Ukraine in 1920, Demjanjuk was a soldier in the Red Army who 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, southern Germany.
Demjanjuk has always insisted 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.
Condemned to death in Israel in 1988, the verdict was 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.
In 1999, the US government filed new charges using fresh evidence that surfaced following the collapse of the Soviet Union, and he was stripped of his citizenship in 2002.