Michaella McCollum and Melissa Reid, who have admitted trying to smuggle drugs out of Peru in August, have been brought to court in Lima.
Ms McCollum, 20, from Dungannon in Co Tyrone, and Ms Reid, 20, from Glasgow, were arrested after 11.5kg of cocaine was found in their baggage as they tried to board a plane to Spain at Lima airport.
The two have pleaded guilty but have maintained they were coerced into carrying the drugs.
Prosecutors say that under Peruvian law a guilty plea is only valid if it is sincere.
They have demanded more information before accepting the admissions of guilt, which the women hope will bring their jail time down to six years and eight months.
The women have been brought back to court at the request of the prosecutor in the case.
The private hearing is taking place before a judge at Sarita Colonia del Callao jail, in Callao.
Earlier, the two women were described as being in "brilliant health" in a modern, well-equipped prison by an Irish priest.
Fr Maurice Foley visited the women last Saturday where he found them sitting under a parasol in a yard in the jail, drinking coffee and making phone calls.
"(They are) brilliant. Very, very well," he said.
"They weren't in a cell. They were out in a wide open space sitting at a table with a parasol. They were talking and drinking coffee.
"As well as that they had telephone communication and they could use it for calling home. I thought they were in great form actually."
Fr Foley had to wait a month to be allowed in to visit the young women because of a flu outbreak in the prison.
They were moved to the modern jail after spending time in the harsh Virgen de Fatima prison in Lima.
Fr Foley said he did not speak to the two about their legal case.
But he said that he took Ms McCollum to one side during the visit and advised her that she should not expect to secure a sentence as low as one year. The priest said he expected a seven-year sentence, which could be reduced at a later stage.
Ms McCollum was very emotional when the priest warned her about the jail sentence. He said the women were sadder and wiser for the experience.
Fr Foley also suggested they might get moved to a new prison in the north of Lima after sentencing, which has an area dedicated for foreigners.
The priest said local media reports had not done the women any favours, with stories saying that they had "behaved badly" in Ibiza and were then sent to Peru to act as mules.