Pena Nieto has been under growing pressure from protesters to end impunity and brutality by security forces since the 43 students were abducted by corrupt police in the southwestern city of Iguala on the night of Sept. 26.
The government says local police handed over the students to a drug gang, which apparently murdered them and then incinerated their bodies. In a speech to an assembly of political leaders, Pena Nieto said: "Mexico cannot continue like this."
"After Iguala, Mexico has to change," he said, noting that the reforms also aimed to create a new law against infiltration by organized crime and redefine powers in the penal system.
The president said he would send an initiative to Congress to unify often multi-layered police forces in Mexico's states and had ordered a special security operation in the Southwest, large swathes of which are plagued by drug gangs.
Pena Nieto said the government would also launch a program to boost growth in economically backward and troubled areas of the country including the Southwest, ensuring they would get preferential financing conditions.