The FAA says 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 announcement by the Federal Aviation Administration comes four months after the agency downgraded the country's aviation safety ranking. In July, the FAA publicly faulted Mexico's oversight of commercial aviation and indicated that efforts to turn things around fell short of international requirements.

The FAA said Mexico has made significant progress and is now upgraded from the Category 2 safety rating the country received in July to Category 1. It is unusual for a country to regain the top U.S. safety ranking, called Category 1, so quickly after being stripped of that rating.

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 - equivalent to the FAA for aviation safety matters - is deficient in one or more areas, such as technical expertise, trained personnel, recordkeeping or inspection procedures.

With the International Aviation Safety Assessment (IASA) Category 2 rating, Mexican air carriers could not establish new service to the United States, but were allowed to maintain existing service. Now with the Category 1 rating, Mexican air carriers can again add flights and service to the United States.