Ciudad Juarez, Mexico ? With 5 million discarded tires littering the background, the United States and Mexico announced an accord Thursday to clean up the mountains of rusty cars, smashed school buses and rotting rubber that are a blight on the border.

Environmental officials from both countries said the first step of the massive cleanup would be to start burning the tires for fuel in cement factories.

“The environmental challenges that we face do not respect political boundaries,” said Richard Green, a regional administrator for the U.S. Environmental Protection Agency. “We experience them together, and we must address them together.

Mexico’s secretary of environment and natural resources, Alberto Cardenas-Jimenez, said Grupo Cementos de Chihuahua and officials of Ciudad Juarez, across the border from El Paso, Texas, had agreed to dispose of 800,000 used tires in each of the next five years.

Ciudad Juarez will pay the cement-maker 31 cents for every tire burned and in turn, Cementos de Chihuahua will use the tires as fuel, investing $2.5 million in equipment at the Samalayuca cement factory, 25 miles south of Ciudad Juarez.

Though the United States is not involved in funding the project, it worked with Mexican authorities in coming up with the plan. The agreement will only make a dent in the estimated 5 million used tires at the city’s collection center. Two million more are scattered in dry gullies and clandestine dumping sites throughout the city, where residents simply throw out tires to avoid paying the $1 fee the city requires to get rid of them.

“These tires have become breeding grounds for disease, carrying mosquitoes, and when they burn, they release hazardous waste to the air and soil making it a grave environmental and health problem for the people of Juarez,” said Alma Leticia Figueroa, director of Ciudad Juarez’s Ecology and Civil Protection Department.

Figueroa said each month firefighters put out about 1,000 fires started by people often trying to get rid of both trash and tires.

In addition, as part of the accord, tires from Tijuana and Mexicali, also popular dumping grounds, will be sent to nearby cement factories to be used as fuel.

Workers pile used tires at the city's collection center in Ciudad Juarez. Mexican and U.S. environmental officials said Thursday they will dispose of thousands of tires by burning them for fuel in cement factories, the first step aimed at cleaning up the rusting sedans and mountains of radials cluttering the border.