Agreeing to new meetings in two weeks on Saturday, the co-president of the Global Committee of Argentina Bondholders (GCAB) said she was "satisfied" so far with initial one-on-one talks.
However, Nicola Stock said the country's biggest foreign creditor group did not touch on the key issue of how much debt creditors should forgive.
Argentina has offered to pay 25 cents in the dollar, a far cry from the 65% or more many creditors want to recover on the $88 billion the country defaulted on in January 2002.
GCAB, which says it represents investors holding $37 billion worth of bad Argentine bonds, must "wait and check after the technical meetings in a couple of weeks".
"We have to see if there is any compromise between the government and the creditors. If there isn't, then again we are in trouble."
Stock, who has had fierce run-ins with the Argentine government in the past, said Friday's closed-door talks with Finance Secretary Guillermo Nielsen were "cordial" between sides that have had heated exchanges through the media.
In a separate statement issued in Rome, Stock said the meetings planned in two weeks' time "should lead to a negotiation on the restructuring of the South American state's debt that is sustainable and fair, both for Argentina and for savers".
Argentina argues it cannot repay more to creditors without endangering a faster-than-expected recovery from deep economic crisis and inflicting more pain on the 50% of the population living in poverty.