All three sides can still join Croatia in progressing out of the tight group, as they are separated by a couple of points ahead of Tuesday's final-round matches.
Nigeria are in the driving seat, sitting two points better off than Argentina and Iceland, with the latter facing off against Croatia in their next match.
Ighalo knows full well just how much is riding on his side's clash with La Albiceleste, and is confident of booking a spot in the next round.
"It's going to be a war and a final of finals because they need to win," he told BBC Sport. "They are going to come all out and use every tactic that they know to win a game. I am expecting it to be a very tough game but I think we are capable of qualifying."
Argentina and Nigeria have faced off on four previous occasions at the World Cup, with the Super Eagles yet to avoid defeat.