The 67-year-old fugitive said: "I'm too old to go running any longer, and I'm not going to disappear.
"If I have to return to jail, so be it. I don't fancy such a prospect, but if that's the way the coin is going to drop, then I'm going to have to face it."
He was speaking as it was reported that an extradition treaty between the two countries could be just a few weeks away.
A Home Office spokeswoman declined to comment on the timetable for the treaty, but said: "It is in the process of being ratified at the moment. Once ratification has taken place, a decision can be taken on whether to request the extradition of Mr Biggs."
After hearing the latest developments, Biggs said: "Nobody knows when the treaty is going to be ratified and until there is a definite request for my return, I can't have a view on where I stand.
"It's been going on since my son was 18, and I've learned to live with it.
"I do have a Brazilian lawyer. I would obviously do whatever I can to avoid being sent back to England, and my lawyers would make a case for me staying here.
"There's a number of reasons why I could be allowed to stay. Number one, I've lived a blameless life in the 27 years I've been in Brazil. If Brazil send me back, I would stay a long time in prison, in all probability I would die there, and I don't think Brazil would be keen to send me back on those terms.
"I am also the father of a Brazilian subject, although he is almost 23.
"But the law is the law, if the extradition treaty does affect me, which I'm not sure about. Many people say it would be absurd to return me to prison. They tell me it's not like it was - I hope it's a more positive experience than it was.
"I'll do whatever I can, but if the outcome is that I must return, I will not run away, I shall return."
Biggs was part of the gang which stole pounds 2.6m from a Royal Mail train on 8 August, 1963. He escaped from Wandsworth prison in July, 1965, after serving just 15 months of his 30-year sentence.Reuse content