In reaction to last week’s move by the U.S. FAA to restore Mexico’s aviation safety rating to Category 1, Aeromexico plans to re-establish code share flights with U.S. partner Delta Air Lines as of December 11. All told, the airline expects to offer 45 daily flights that share the Delta Air Lines code.

Effective today, Aeromexico added a single flight to existing service to New York, Miami, Chicago, Los Angeles and Las Vegas. The airline also plans to add two daily frequencies to San Antonio, Texas, starting January 11, increasing Grupo Aeromexico’s offering between Mexico and the U.S. to 434 weekly flights.

The FAA announced on December 1 that Mexico again complies with international safety standards set by the International Civil Aviation Organization (ICAO), based on the results of a November FAA review of Mexico’s civil aviation authority. The FAA noted that Mexico had made “significant progress” under the leadership of Secretary Juan Molinar and Director General Hector Gonzalez Weeks since downgrading its status from Category 1 to Category 2 in July. At Mexico’s request, the FAA will continue to provide technical assistance to support and maintain the changes the civil aviation authority has already made, the U.S. agency said in a statement.

A Category 1 rating means the country’s civil aviation authority complies with ICAO standards. A Category 2 rating means a country either lacks laws or regulations necessary to oversee air carriers in accordance with minimum international standards, or that its civil aviation authority shows deficiencies in one or more areas, such as technical expertise, trained personnel, recordkeeping or inspection procedures. The FAA does not release details of its safety reviews or elaborate on its findings.

With the International Aviation Safety Assessment (IASA) Category 2 rating, Mexican air carriers could not establish new service to the U.S., but could maintain existing service.

As part of the FAA’s IASA program, the agency assesses the civil aviation authorities of all countries with air carriers that operate or have applied to fly to the U.S. The assessments determine whether or not foreign civil aviation authorities meet ICAO standards, not FAA regulations.