A plea deal between extradited Briton Christopher Tappin and US prosecutors is the beginning of his "swift and safe return" to the UK, his wife has said.
The retired British businessman is expected to reach a deal with prosecutors on Thursday over charges of conspiring to sell batteries for Iranian missiles.
His wife Elaine said "however upsetting" a plea deal was, it marked the beginning of his "swift and safe return" to the UK.
Mrs Tappin, who has chronic Churg-Strauss syndrome, said: "From the moment Chris was put on a plane all we ever wanted was his swift and safe return.
Tappin, 65, is charged with conspiring to sell batteries for Iranian missile systems
"However upsetting, this is the beginning of that process.
"It would be inappropriate to comment further whilst the Court has yet to establish Chris' fate."
Tappin, 65, of Orpington, Kent, is on bail and will appear in court in El Paso, Texas, on Thursday to hear prosecutors set out the terms of his plea bargain, a family spokeswoman said.
If the terms are agreed by senior US district judge David Briones, it is likely to be several weeks before he is sentenced.
He faces up to 35 years in jail, but this is likely to be significantly reduced under the terms of any plea deal.
David Bermingham, who was one of three bankers jailed for 37 months over an Enron-related fraud in a deal with US prosecutors in 2008, said in March that no sane defendant would risk dozens of years in jail when a plea bargain could enable them to be home within months.
Plea bargaining is common in the US, with defendants often able to secure a more lenient sentence if they admit an offence and co-operate with prosecutors, rather than contest the charges in a trial.
But the system, and the pressure it places on defendants, leaves those extradited to the US from the UK with little choice but to accept a deal if they want to return to their families at home, Bermingham, of Goring, south Oxfordshire, claimed in March.