The Environmental Protection Agency released initial details of a pilot program that would measure diesel exhaust emissions during highway use with portable, onboard emission measurement systems.

WASHINGTON — Environmental Protection Agency officials said the agency would push for all 11 million diesel engines in the country to be retrofitted within 10 years in order to reduce their emissions of particulate matter.

The United States seeks to encourage trucking companies to reduce exhaust emissions as a way of improving air quality at the southern border and hopes to enlist the aid of Mexico in a coordinated effort, a U.S. Environmental Protection Agency official said.