President Enrique Pena Nieto has visited the tumultuous southern state of Guerrero for the first time since 43 college students disappeared there more than two months ago, provoking the greatest crisis of his presidency.

Pena Nieto travelled to the beach resort of Acapulco on Thursday to announce a plan to spur economic growth one day after the government said federal police and soldiers would take over policing duties in 30 cities, including some in Guerrero.

Pena Nieto called for Mexico to overcome "this painful period." It was set off when police in the city of Iguala intercepted the students and allegedly turned the students over to members of the Guerreros Unidos gang, who subsequently killed them and burned their bodies.

The disappearances have ignited weeks of protests, including in Acapulco.