British businessman Christopher Tappin has made his first appearance in court after being extradited to the US.
Mr Tappin, who lost his two-year battle against being sent to America last week, faces up to 35 years in jail if convicted over arms dealing charges.
Last night he appeared for a five-minute preliminary hearing in the federal court in El Paso, Texas, and was remanded in custody to appear for a bail hearing on Friday.
Attorney General Dominic Grieve said his extradition had highlighted problems with the treaty between the UK and US, which are not "readily curable".
He warned that Britons were left uneasy when faced with the seemingly harsh and disproportionate sentences in the American justice system.
Mr Grieve said: "I think there's a lack of public confidence in the US justice system, which is a rather wider issue and more complicated than the minutiae of the treaty agreement.
"There are perceptions in this country that the US criminal justice system can be harsh, its penal policy can be harsh, and its sentencing policy can appear disproportionate by European and British standards.
"There are aspects of it therefore which tend to make people uncertain and uneasy, and I'm not sure that that's readily curable."
Mr Grieve admitted the UK's extradition laws were not ideal, but said: "In a world where we wish to see crime successfully combated, having a system by which to facilitate transfer to countries which meet the necessary criteria of fairness so as to curb crime is absolutely indispensable."
Mr Grieve was speaking as he gave evidence to MPs yesterday, minutes after Mr Tappin's wife Elaine, 62, broke down in tears as she told them of her despair that nobody was prepared to listen to his defence before "carting him off".
Mrs Tappin told the Commons Home Affairs Select Committee's review of extradition arrangements that her family felt "incredulity, frustration, heartrending sadness, despair and utter disbelief" as they faced a "wholly uncertain future".
In a written statement which she was unable to finish reading, Mrs Tappin went on: "At the heart of our despair is the fact that nobody was prepared to listen to Chris's defence before carting him off.
"They ticked the boxes but were deaf and blind to the possibility of injustice."
Mrs Tappin, of Orpington, Kent, said she had still not been able to talk to her husband since he was extradited and he was being held in isolation, "locked up for 23 hours a day".
She said it was the "cruellest blow" when her husband lost his battle against extradition, saying he "was stunned and totally devastated when his appeal was rejected".
Just last week she tearfully accompanied her husband to Heathrow Airport, before he was handcuffed and seated between two US marshals on a plane to America.
Mr Tappin, the president of the Kent Golf Union, denies attempting to sell batteries for surface-to-air missiles which were to be shipped from the US to Tehran via the Netherlands.
Human rights organisations have condemned his extradition while his MP, Tory Jo Johnson, and UK Independence Party leader Nigel Farage, who has known the businessman for nearly 40 years, have asked Home Secretary Theresa May to intervene to ensure the US authorities do not object to bail when he appears in court on Friday.