The PNG anti-corruption watchdog issued a warrant for O'Neill's arrest in June 2014.
The outstanding warrant relates to allegations O'Neill personally authorised the illegal payment of about $31 million (US$22.8 million) to law firm Paul Paraka lawyers.
O'Neill said that the legal case was taking its course.
“Show me where I have received one toea (PNG coins) or one Kina (cash currency) and I will resign tomorrow,” he told the National Press Club in Canberra on Thursday.
He insisted the lawyer concerned was employed by the previous government.