WASHINGTON (Reuters) - U.S. Attorney General Bill Barr on Friday said he opposed legislation under consideration in Mexico that would put tough restrictions on foreign agents operating in the country, including those fighting the drug trade. Mexico’s Senate approved a bill on Wednesday widely seen as a broadside against the United States, after weeks of tension with Washington over counternarcotics operations. It will next be considered by the lower house. The proposed law does not specifically target the United States, but was proposed by President Andres Manuel Lopez Obrador after a diplomatic flare-up over the arrest of former Mexican Defense Minister Salvador Cienfuegos in Los Angeles in October on drug charges. Lopez Obrador threatened to review security cooperation with the United States after the arrest, and U.S. prosecutors dropped the charges, pointing to “sensitive” foreign policy considerations. Barr said the law under consideration would benefit transnational criminal organizations. “We are troubled by legislation currently before the Mexican Congress, which would have the effect of making cooperation between our countries more difficult,” he said in a statement. ADVERTISEMENT “Our cooperation takes place within the longstanding framework designed to address jointly our shared challenges: that is why, for example, the United States recently returned former Secretary Cienfuegos to Mexico, in order to allow him to be investigated there,” he added. Ricardo Monreal, Senate leader of Lopez Obrador’s National Regeneration Movement (MORENA), has said the legislation was not aimed at any particular country. But he has also complained pointedly that U.S. Drug Enforcement Administration was not transparent about matters such as how many DEA agents there are in Mexico. Reporting by Diane Bartz; Editing by Tom Brown