MEXICO CITY, Dec. 21 (Xinhua) -- The construction of Mexico City's alternative airport will begin in January 2019 at the Santa Lucia military base, Mexican President Andres Manuel Lopez Obrador said Friday.

The president said in a conference that the excavation and land preparation will begin at the beginning of 2019 and the construction on a third runway will begin in March.

Lopez Obrador said the armed forces will carry out the construction to convert the military airstrip into a commercial airport.

According to the budget for the federal government, an initial 503 million U.S. dollars will be invested. The total amount of the project is estimated at 3.521 billion U.S. dollars.

The federal government, which took office on Dec. 1, canceled the construction of the New International Airport for Mexico City in the municipality of Texcoco because it was too costly.

The new international airport, a project valued at 13.3 billion U.S. dollars, was the main infrastructure project of ex-president Enrique Pena Nieto's government to ease the traffic congestion at the current Mexico City International Airport.

Under Lopez Obrador's plan, the current Mexico City International Airport will continue to operate for domestic flights, and international operations will be transferred to Santa Lucia in conjunction with Toluca International Airport, some 60 km from Mexico City.

To accomplish this, both Mexico City International Airport and the Toluca International Airport will be modernized and the work is also expected to start at the beginning of 2019.