The lawyer for a former fighter pilot has said his client is "acutely disappointed" the Attorney-General has approved a request for his extradition from Australia to the US.
Former US marine Daniel Edmund Duggan, 54, has been in custody since he was arrested by the Australian Federal Police in Orange last October.
Sydney's Downing Centre Local Court was told Attorney-General Mark Dreyfus accepted a request just before Christmas from the US to extradite their former citizen.
It is understood the order relates to Mr Duggan's former work in China training local pilots, but the charges remain sealed.
Outside court, his lawyer Dennis Miralis said his client would fight the extradition order and disputes the accusations he has seen so far.
"We will continue to maintain vigorous lines of communication with the Attorney-General," Mr Miralis said.
"Mr Duggan is presumed to be innocent under US law.
"[He] has expressed his grave concern about the ongoing impact this will have on his family and particularly his six children."
He said Mr Duggan's activities in China were not unusual and his client was being unfairly singled out for political gain, when several other Australians had performed services to foreign countries without any issue.
Mr Miralis said his client was being held in Silverwater jail, in a segregated area alongside convicted terrorists, in breach of the Extradition Act.
He has accused the NSW Department of Corrections of taking instructions from the US, in order to treat his client differently.
"Mr Duggan remains under extraordinary stress as a result of the current restrictions imposed on him in custody," Mr Miralis said.
He said documents provided to the court only outlined the "bare skeleton" of the allegations against his client, which was standard in extradition hearings.
A magistrate will consider Mr Duggan's eligibility to be extradited before the final decision is left to the Attorney-General.
The matter is due before court again on February 13.
