Attorney General Arely Gómez said that international experts will participate.
This will help the experts to prepare their report.
It wants to clarify what happened to alleged kidnappers after their arrest.
José Trinidad Loza Ventura is on death row.
The team from the Inter-American Commission on Human Rights said Monday in a news conference that the government wrote on Sunday that officials are still analyzing the request three months after it was made. The group said the delay limited its ability to advance.
The IACHR urged Mexico to implement international standards regarding the use of force in immigration control operations.
Experts from the IACHR want to talk to soldiers presumably involved in the disappearance of the students.