She joined the mayors of Paris, Athens and Mexico City in signing the deal to improve air quality at the biennial meeting of city leaders in Mexico on Thursday.
She also vowed to continue in a drive for alternative vehicle use and improve conditions for cyclists and pedestrians in the city.
Madrid is recognized as the most polluted city in Spain, a nation where 29,980 deaths were attributed to air pollution in 2013, according to the Air quality in Europe – 2016 report, published by the European Environment Agency (EEA) last week.
Madrid has introduced a raft of measures aimed at improving air quality including lowering the speed limit when contamination levels get too high and imposing a ban on non-residents driving into the city.
Parked is banned in the center of Madrid when pollution levels reach too high. Photo: Jessica Jones