The U.S. Geological Survey revealed that the quake had a magnitude of 7.1 and was centered near Raboso in the state of Puebla which is about 76 miles (123 kilometers) southeast of Mexico City.
People gather on a Mexico City street after office buildings were evacuated because of the quake. Officials said at least 22 children were killed when the school building collapsed, dozens of others are missing.
Pea Nieto also expressed condolences to those who had lost a family member or loved one in the quake and reported that 40 percent of Mexico City and 60 percent of Morelos state were still without power.
A magnitude 7.1 natural disaster caused buildings to sway and break apart in Mexico City on the anniversary of the magnitude 8.0 quake that did major damage in 1985.
It's Mexico's second major quake this month. REUTERS/Ginnette RiquelmeA rescue worker motions for everybody to be quiet as they are searching for people under the rubble of a collapsed building after an quake hit Mexico City, Mexico September 19, 2017.
President Donald Trump, who has clashed with Peña Nieto over his repeated calls for a border wall between their countries, sent his support in a tweet. Amidst the chaos, Juan Magana, a man who was vacationing in Mexico City say luckily the damage to his hotel wasn't severe, but he did witness several people in distress. A six-storey blocks of flats, a supermarket and a factory were also said to be among the collapsed buildings in the city. Morelos, just to Mexico City's south, saw 71 deaths.
Javier Trevina, the education secretary, told local news media that eight adults also died when the school collapsed. REUTERS/Edgard GarridoPeople pass buckets and shovels to remove the rubble of a collapsed building after an quake hit Mexico City, Mexico September 19, 2017. "We are with you and will be there for you", the president wrote on Twitter.